Tag Archives: weather

The new climate normal: Extreme, “once in a century” floods rip houses, kill dozens in Western Europe

Dozens of people were killed and even more are missing after torrential rains triggered extreme floods in Germany and neighboring Belgium. While at this point, we can’t say with certainty that the floods were caused by climate change, experts believe these are once-in-a-century type floods — and climate change is known to amplify this type of extreme events.

In the peaceful, wine-growing, hilly Eifel region in Germany, six houses collapsed, and a further 25 buildings are at extreme risk of caving in. At least 70 people are missing, and 44 were confirmed killed already. Belgium is also affected, as is the Netherlands.

Western Europe is not prone to flooding, or any extreme weather events for that matter. But this summer, heatwaves, floods, and even tornadoes seem to be on the table.

“There are people dead, there are people missing, there are many who are still in danger,” the governor of Rhineland-Palatinate state, Malu Dreyer, told the regional parliament. “We have never seen such a disaster. It’s really devastating.”

German Chancellor Angela Merkel said she was distraught by the news of the floods. “My sympathy goes to the relatives and of the dead and missing,” she said during a trip to Washington.

The situation is still unfolding, and the full extent of the damage is not yet known. To make matters even worse, the worst may not yet be over — authorities are bracing themselves for more rain today, although drier weather is expected over the weekend.

This level of rainfall has not been seen in one hundred years. Local municipalities have basically seen two months of rainfall in a single day. Meanwhile, high temperatures of over 30 degrees Celsius (86 degrees Fahrenheit) are expected in parts of northern Europe, and the night between Wednesday and Thursday was the hottest in Finland’s history.

While it’s very difficult to link individual weather events to larger climate change shifts, researchers have warned for decades that these shifts will bring more extreme weather events like floods and heatwaves. Even a tornado hit the central European nation of Czech Republic, killing five people in the process.

These once-in-a-century extreme weather events are expected to become more and more common as the new climate normal enters into force. The current climate shifts are driven by man-made greenhouse gas emissions, and will continue to accentuate as long as we continue emitting.

Armin Laschet, the conservative candidate to succeed Merkel as chancellor at a general election in September and the premier of the hard-hit state of North Rhine Westphalia, also pointed this out during a visit to the area:.

“We will be faced with such events over and over, and that means we need to speed up climate protection measures, on European, federal and global levels, because climate change isn’t confined to one state,” he said.

May was the sunniest month on record in the UK — and climate change might be behind it

The world-famous British gloomy weather is going through a transition, and climate change might be behind it. May was the sunniest calendar month on record in the UK, continuing a trend that saw the sunniest British spring thus far, according to data from the Met Office.

Green Park in London. Credit Flickr

Following a drenching winter with record rain, the UK had 266 hours of sunshine in May – besting the previous record of 265 hours from June 1957. A record was also broken in spring, with 626 hours of sun, compared to the 555 hours registered in 1948, the previous record-breaking year for sunny days.

This sudden switch from extremely wet to extremely dry surprised meteorologists, claiming this doesn’t seem like British weather. The UK gets on average 436 hours of sun between March and May. Since 1929, only 10 years had more than 500 hours – with none seeing more than 555 hours.

“We’ve swung from a really unsettled spell with weather systems coming in off the Atlantic to a very, very settled spell,” Professor Liz Bentley, chief executive of the Royal Meteorological Society, told BBC. “It’s unprecedented to see such a swing from one extreme to the other in such a short space of time. That’s what concerns me.”

Warm weather at the end of May offset cooler conditions earlier in the month, the Met office reported, adding that the month was warmer than average but not exceptionally so. It has been the driest May in England and second driest in Wales with 9.6mm and 14.3mm, respectively.

Is it due to climate change?

The Met Office said this is not an indicator of the future, because the jet stream might behave differently. Meteorologists believe man-made climate change may be implicated but said it is too soon to tell. The rapid heating of the Arctic may be influencing the jet stream, although that is not proven.

Professor Joe Smith, chief executive of the Royal Geographical Society, told the BBC: “In a wider context it’s a signal of the increasing unpredictability of the UK’s climate. The fact remains that bold early actions to slash emissions can still cut the larger risks associated with climate change in the UK and around the world.”

Weather is part of the UK identity, with more than nine in ten that have talked about it in the last six hours, according to a survey. Britain’s geography has made its weather mild, changeable, and famously unpredictable. The variability means residents never know quite what to expect

Climate change is causing warming across the UK, according to research by the Met Office. All of the UK’s ten warmest years on record have happened since 2002. Heatwaves are now 30 times more likely to happen due to climate change. Winters are projected to become warmer and wetter on average.

2019 was the second warmest year on record, NASA and NOAA found

Independent analyses from NASA and the National Oceanic and Atmospheric Administration (NOAA) found that 2019 was the second warmest year on record since 1880.

Yearly differences in temperature for 2019 (black line) and the other ten warmest years on record compared to the 20th-century average.
Image credits Global Climate Report – Annual 2019 / NOAA.

Global surface temperatures in 2019 were the second warmest in modern records (the keeping of which began in 1880). This makes the past five years the warmest in the last 140 years, the agencies explain, with the highest temperatures recorded in 2016.

Hot trend

“The decade that just ended is clearly the warmest decade on record,” said Goddard Institute for Space Studies Director Gavin Schmidt. “Every decade since the 1960s clearly has been warmer than the one before.”

Compared to the average temperature between 1951 and 1980, the past year was 1.8°F (1°C) warmer overall, and 2°F warmer than the average temperature in between 1880 and 1900, NASA and NOAA found. Measurement practices change over time, as do the locations of weather stations, so there are some uncertainties in the dataset. However, researchers at NASA estimate that the mean temperature for 2019 is accurate within 0.1 degrees Fahrenheit, with a 95% certainty level.

The team at NASA used surface temperature measurements from more than 20,000 measurement points on the sea, and from Antarctic research stations. The dataset was processed through an algorithm that accounted for location and urban heat island effect to produce yearly temperatures, which were then compared to the baseline period of 1951 to 1980. In broad lines, the NOAA team used the same raw data but processed it differently in the polar areas and data-poor regions, focusing specifically on the year 2019.

Climate modeling, based on the temperatures on record, points to increased human emissions of CO2 and other greenhouse gases in the atmosphere driving this warming trend.

“We crossed over into more than 2 degrees Fahrenheit warming territory in 2015 and we are unlikely to go back,” Schmidt said.

“This shows that what’s happening is persistent, not a fluke due to some weather phenomenon: we know that the long-term trends are being driven by the increasing levels of greenhouse gases in the atmosphere.”

Still, while 2019 was the second hottest year globally, weather dynamics have a strong influence on regional temperatures. NOAA found that for the contiguous 48 United States, 2019 was just “warmer than average,” is the 34th warmest year on record.

In contrast, mean temperatures in the Arctic have been rising three times faster than anywhere else in the world since 1970. Together with a warming ocean, atmospheric temperatures are driving ice loss in Greenland and Antarctica, and an increase in extreme events such as heatwaves, wildfires, and intense precipitation.

Scientists have found a record-breaking 500-km-long mega lightning bolt

Credit: Pixabay.

Some thunderstorms are so intense that the vivid lightning and crashes of thunder may keep you up at night. Here’s a thought that will surely keep you awake during such restless storms: some lightning bolts are so large they can extend across multiple states. According to scientists who analyzed satellite imagery, one such lighting bolt measured more than 500 kilometers (310 miles).

Mega flashes

Since the 1950s, researchers have been aware of lightning discharges on the order of 100 km in length, thanks to radar-based findings. Later, around 1989, scientists discovered “sprites” — large-scale electrical discharges that occur high in the atmosphere at about 50−90 km, within so-called “mesoscale convective systems” (MCSs). One such sprite, which formed in 2007 over Oklahoma, was 321 km in length and has been certified by the World Meteorological Organization as the longest officially documented lightning flash.

But, this kind of record will be broken time and time again in the near future, judging from a recent study published in the Bulletin of the American Meteorological Society.

The study, authored by Walter Lyons at FMA Research in Fort Collins, Colorado, and colleagues, employed ground-based lightning detectors and an instrument aboard the GOES-16 spacecraft, which was launched in 2016. On October 22nd, 2017, the Geostationary Lightning Mapper (GLM) sensor on the spacecraft detected “a lightning discharge that originated in northern Texas, propagated north-northeast across, Oklahoma, fortuitously traversed the Oklahoma LMA (OKLMA), and finally terminated in southeastern Kansas.” According to Lyons and colleagues, the discharge was more than 500 km long, illuminating an area of 67,845 square kilometers.

Such exceptional sprites are the result of propagating lightning channels that tap into huge reservoirs of positive charge present within a MCS’ stratiform region. According to the researchers, typically a lightning discharge originates near the top of the convective cell (~8-10 km in altitude), then travels rearward and downward, following the trajectory of descending positively charged ice crystals.

Although the 2017 megaflash originating in Texas dwarfs the current official record holder for the longest lightning flash, researchers expect to encounter even larger ones. Already, other scientists claim they’ve spotted flashes as long as 673-km in the GOES data. In the future, these observations will help researchers gain a better understanding of how electrical events in the atmosphere occur.

“A megaflash, once initiated, appears able to propagate almost indefinitely as long as adequate contiguous charge reservoirs exist in the secondary precipitation maxima of MCS stratiform regions. Is it possible that a future megaflash can attain a length of 1,000 km? We would not bet against that. Let the search begin,” the researchers wrote.

Researchers uncover how the freak cold wave of 2018 formed

New research is uncovering the source of the extreme cold wave that hit Europe and Asia during the winter of 2018.

Image via Pixabay.

Last winter, around February, a mass of extremely cold air descended upon Eurasia. The record-breaking cold came from the splitting of a body of air high above the Arctic called the polar vortex, and lasted for almost a month. However, at the time, the incoming mass of cold air wasn’t spotted until it was already upon us.

New research is looking into the origins of this event in a bid to help predict similar weather in the future.

A recipe for cold

“It’s one mechanism that potentially explains a third of these events historically,” said Simon Lee, an atmospheric scientist at the University of Reading, UK, and lead author of the new study. “That just one event in the Atlantic has contributed to a third of them is quite surprising.”

The study reports that a cyclone-induced chain of events led to warming in the stratosphere in 2018 and caused the Arctic polar vortex to split in two, causing the extreme cold. Weather forecast models weren’t able to anticipate the stratospheric warming until the start of February, roughly 2 weeks before it happened, which prevented them from anticipating the extreme cold that followed.

The stratosphere is the second layer of the Earth’s atmosphere. It’s a generally cool, dry place, and it’s also the home of the Arctic polar vortex, which circulates around Earth’s North Pole. If average temperatures in the stratosphere go up, the polar vortex weakens and splits in two, which can cause outbreaks of cold weather across the Northern Hemisphere.

Such stratospheric sudden warming events are generally predicted by observing the troposphere (the part of the atmosphere that we live in). We look at how the troposphere behaved prior to stratospheric events, then we build models to predict what’s going on up there based on what we’re seeing down here. But, these models are imperfect and don’t always catch how temporary weather patterns influence the stratosphere.

The study reports that a cyclone-induced chain of events led to warming in the stratosphere in 2018 and caused the Arctic polar vortex to split in two, causing the extreme cold. Weather forecast models weren’t able to anticipate the stratospheric warming until the start of February, roughly 2 weeks before it happened, which prevented them from anticipating the extreme cold that followed.

Looking at historic weather data, the team found that the same series of events has caused sudden stratospheric warmings in the past. The same unusual weather patterns occurred 49 times between 1979 and 2017, before 35% of the stratospheric warming events recorded over this period.

The team says that their findings help flesh out our understanding of sudden stratospheric warming events. The data suggests that looking for changes in the air masses over Greenland and Scandinavia could help predict extreme cold outbreaks in the future, with weeks or months in advance.

The paper “Abrupt Stratospheric Vortex Weakening Associated With North Atlantic Anticyclonic Wave Breaking” has been published in the Journal of Geophysical Research: Atmospheres.

Climate warming changed rainfall patterns across the Northern Hemisphere

Winter precipitation patterns across the Northern Hemisphere are shifting due to climate heating, a new paper reports.

A team led by researchers at the National Center for Atmospheric Research (NCAR) has isolated the effect of man-made climate change on winter precipitation across the Northern Hemisphere. They report that our lifestyle has significant impacts on wintertime rain and snowfall.

When it rains it pours

“I thought this was quite revealing,” said NCAR senior scientist Clara Deser, a co-author of the study. “Our research demonstrates that human-caused climate change has clearly affected precipitation over the past 100 years.”

The team used a novel approach to tease apart artificial and natural elements that affect the patterns of precipitation and their effects. The researchers drew on records and observations of precipitation and large-scale atmospheric circulation patterns, along with statistical techniques and computer climate simulations. In the end, they identified the amount of average monthly precipitation in specific regions of North American and Eurasia that fell as a result of human impact on the climate, rather than natural variability.

Rises in mean temperatures associated with human-caused emissions of greenhouse gas have noticeably increased wintertime precipitation over wide swathes of northern Eurasia and eastern North America since the 1920s, the team reports.

The findings can help to improve our understanding of how climate change can impact precipitation across the globe. Globally, precipitation is projected to increase by an average of 1-2% for each additional degree Celsius of increase in mean temperatures, because a warmer atmosphere holds more water vapor. Local changes, however, may make some regions become drier and others far wetter than they are today.

It’s not easy teasing apart man-made from artificial elements when it comes to precipitation, as this is affected by many local factors and conditions that can vary from day to day or year to year. In this chaotic setting, it’s virtually impossible to establish reliable long-term trends.

Previously, scientists relied on large numbers of climate model simulations to determine the influence of a changing climate on precipitation. In this present study, however, the team started with observed data. In essence, their approach can be summed up as: if you take away the precipitation caused by natural factors, and then compare that to what was recorded on the ground, you can tell how much of it can likely be attributed to human-driven changes in climate.

A) Observed precipitation trends overall; B) Dynamical contribution to A. C) A-B.
Image credits Ruixia Guo et al., 2019, AGU.

The approach used by the team is known as dynamical adjustment. It’s based on statistical techniques applied to observed data — the team used observations of large-scale circulation patterns in the atmosphere for every winter month from 1920 to 2015. Such circulation patterns occur independently of atmospheric greenhouse gas levels.

After crunching all the data, the team could estimate the average amount of precipitation that would be produced by a particular circulation pattern. They then compared these results to measured levels of precipitation to reveal the influence of climate change.

Northeastern North America, as well as a small part of northwestern North America, has experienced more precipitation due to man-made climate change, the team reports. Much of northwestern and north-central Eurasia fares similarly.

In contrast, parts of central and southwestern North America may have experienced drying, although not enough to offset natural variability, they add. Much of southern Eurasia is also experiencing drying as a result of climate change. However, the authors cautioned that their results for those regions were less pronounced and not statistically significant.

The team focused on winter because winter precipitation is driven by broad atmospheric patterns that are easier to see in the data than localized conditions that affect summer precipitation (such as soil moisture and individual thunderstorms), the team explains. The Northern Hemisphere simply has more and better-quality precipitation recordings, so they focused the study here.

The results fit with climate model simulations of human-caused changes in precipitation, which helps verify the models.

“Scientists previously turned to climate models for answers. Here, the climate models come in only at the end to confirm what we teased out of observations independently,” said NCAR scientist Flavio Lehner, a co-author of the study.

“I think this is the major scientific breakthrough of this work.”

Lehner and Deser used the same technique in a separate study published in Geophysical Research Letters last year, to show that recent drying in the U.S. Southwest is largely attributable to natural variability.

The paper “Human Influence on Winter Precipitation Trends (1921–2015) over North America and Eurasia Revealed by Dynamical Adjustment” has been published in the journal Geophysical Research Letters.

A hotter Arctic means more extreme weather elsewhere on the globe

A new computer model confirms that the warming Arctic produces strong winds and extreme weather in the northern hemisphere, where 90% of Earth’s population is living.

Clouds along a jet stream over Canada. Image credits: NASA.

We often talk about climate change as if it’s a uniform thing, but the planetary average is not representative of all the places on Earth. Since 1901, the planet’s surface has warmed by 0.7–0.9° Celsius, but the Arctic area has warmed up almost twice as much, and Alaska and western Canada’s temperatures have risen by 3 to 4 °C.

At first glance, you might think that’s a good thing. After all, very few people live in the Arctic, and its ecosystem also isn’t particularly rich. However, what’s happening in the Arctic can have cascading effects on the rest of the planet. For instance, it means that snow and ice will melt at an accelerated pace, giving way to darker soil and water, which absorb even more solar energy and create a warming feedback loop. Melting ice also causes sea level rise, as well as the release of methane trapped in the Arctic permafrost. Also, a warming Arctic can mess up the global wind circulation, particularly something called the jet stream.

Jet streams are fast flowing, narrow, meandering air currents, typically marking the boundary between the cold polar air and the warmer air mass to the south. For decades, researchers have tried to assess the impact that climate change has on the Arctic jet stream, and the cascading effects this impact will have on local weather in the northern hemisphere.

Depiction of the polar jet stream, can travel at speeds greater than 180 km/h (110 mph). Higher wind speeds colored in red. Image credits: NASA/Goddard Space Flight Center.

In recent years, wind data shows that these jet streams increasingly faltering. They are also changing course, being less often parallel on the Equator, and instead, sweeping across different areas of the northern hemisphere. This does not only cause strong winds locally, but also injects cold Arctic air into lower latitudes, as was the case with the extreme cold that struck the Midwest of the USA in late January 2019. At the same time, a weakened jet stream can lead to prolonged heatwaves and drought, as was experienced in Europe in 2015 and 2018. In other words, although some politicians seem to have difficulties grasping this concept, climate change altering the jet stream can produce more extreme weather — both cold and warm.

However, while the general principle was clear, the observations did not exactly fit the existing climate models — until now. The breakthrough came when researchers incorporated ozone chemistry into their model using a new machine learning algorithm. When this was added to existing models, the results fit the observations perfectly.

“We’ve developed a machine learning algorithm that allows us to represent the ozone layer as an interactive element in the model, and in so doing, to reflect the interactions from the stratosphere and ozone layer,” says first author and atmospheric researcher Erik Romanowsky. “With the new model system we can now realistically reproduce the observed changes in the jet stream.”

The reason why ozone is important is that sea-ice retreat creates an area of ozone-amplified warming in the polar stratosphere. This warming is counterbalancing the frigid temperatures which act as the engine of the jet stream, essentially weakening these air currents.

In turn, this indicates that it’s not just the warming directly, but the loss of sea ice that’s causing changes in the jet stream.

“Our study shows that the changes in the jet stream are at least partly due to the loss of Arctic sea ice. If the ice cover continues to dwindle, we believe that both the frequency and intensity of the extreme weather events previously observed in the middle latitudes will increase,” says Prof Markus Rex, also an author of the study. “In addition, our findings confirm that the more frequently occurring cold phases in winter in the USA, Europe and Asia are by no means a contradiction to global warming; rather, they are a part of anthropogenic climate change.”

The study also represents an important technological achievement — the use of machine learning to substantially improve climate models and improve our understanding on the planet we live on.

Journal Reference: Romanowsky et al. The role of stratospheric ozone for Arctic-midlatitude linkages. Scientific Reports, 2019; 9 (1) DOI: 10.1038/s41598-019-43823-1

Weather and crime: is there a connection?

Credit: Pixabay.

Some of the most interesting and informative aspects of criminal investigations are the motives and social or environmental conditions that contributed to specific criminal acts. From substance use to socioeconomic background and exposure to violent media, experts have attempted to understand the factors that make particular types of crimes more likely or that correlate to an increased overall crime rate. Studies in this area have made it clear that the circumstances that promote violence and crime are just as complex as the motivations of the perpetrators.

Recent research has tied a rise in crime rates to an environmental factor: the weather. Between extended cold spells to blistering summer heat, temperature and weather conditions have taken the blame for increased criminal activity in many different news stories covering a range of locations. In many cases, law enforcement officers and others seem convinced that atmospheric factors play a role in crime rates, but does the evidence actually show a correlation between weather and crime?


Fortunately, multiple studies have been completed to determine whether there is any truth to the claims that weather conditions in either extreme contribute to an increased likelihood of criminal activity. These studies have provided important insights into the ways that temperature influence the frequency of certain crimes.


Tracking ambient temperature and crime rates, a Finland study used nearly two decades of data to identify a possible connection between them. Researchers found that temperature changes were responsible for 10 percent of fluctuations in the nation’s crime rates — a 1.7 percent increase in criminal activity for each degree centigrade rise in the temperature. More specifically, the study found that increased serotonin levels resulting from high temperature likely contributed to increased impulsivity and a higher risk of crimes.

A recent comparison of crime and temperature data across ten major U.S. cities echoed the findings of the Finland study. Looking only at the number of shootings, the investigation found that as temperatures rose, so did the number of shooting victims in nine out of the ten cities (the outlier, San Francisco, has weather patterns that are notably more moderate). Additional details provided by the city of Philadelphia reveal that the crime increase comes solely from outdoor incidents – the number of indoor shootings stayed the same despite dramatic changes in temperature.


Another major American city, Chicago, provides further insights into the impact of weather and temperature on crime rates. Police crime data from the City of Chicago Data Portal indicates that within the annual summer crime peak, certain types of crime appear more weather-dependent. Out of seven major crime categories, theft, along with shootings and other battery, saw the greatest increase as temperatures rose, with nine additional incidents for every 10-degree temperature increase.

Other categories of crime are correlated to a lesser extent, including criminal damage (five more incidents per 10-degree increase) and assault (three additional incidents). Burglary, narcotics and homicide were significantly impacted by weather variations, limiting the correlation of temperature to certain types of crime.


This trend of violent crimes rising with the temperature has been corroborated by several studies across the globe, but it appears to be the only weather condition that relates to an increase in crime. Data collected in the South African city of Tshwane found significantly higher rates of violent, sexual and property crimes on the hottest days; violent crimes in particular rose 50 percent compared to the city’s coldest days. Rainfall had a much less noticeable relationship to crime rates, with a decrease in violent and sexual crimes, and only a 2 percent increase in property crimes.

Similarly, during cold weather conditions (ranging from standard winter to brutal blizzard conditions), crime instances tend to decrease. Knowing that hot weather is a factor in crime rates is valuable for law enforcement, and even more important is understanding why temperature seems to have such an influence on violence.


Current research and scholarship around the connection between temperature and crime, especially the most violent crimes, provides insights into the reason behind this intriguing correlation. Two main theories have been presented as the key reasons that hot temperatures may encourage additional criminal activity: the increase in opportunities for crime and the changes in temperament that result from warmer weather.


One of the most obvious explanations for weather’s apparent impact on crime is that warmer temperatures in general provide more opportunities for crime. Especially compared to cold or stormy weather, warm summer days encourage more time spent away from the home and more outdoor activities.

Along with increased opportunities for property-related crimes, there is an increase in interactions between people. Statistically speaking, more interactions provide a higher likelihood of a violent or criminal encounter. The Philadelphia study mentioned above is clear evidence of this connection between weather and opportunity.


The other element that is often referenced in warm weather’s influence on crime is a change in temperament that occurs along with the change in temperature. In the Finland study, hot temperatures were linked to changes in brain chemistry that made impulse and aggressive actions more likely — and it is far from the only research to make this connection.

Craig Anderson, leader of Iowa’s Center for the Study of Violence and expert in human aggression, explains that heat doesn’t cause violence but does tend to encourage it. As an example, hot temperatures make it more likely a pitcher will hit the player at-bat, but only after a batter on the pitcher’s team has been hit. The heat escalates situations by causing people to perceive more aggression in certain acts than may be intended. In other words, the mental effect of a warm day that makes you more likely to honk your horn is the same one that contributes to greater violence in the heat of summer.


The insight that hot temperatures do, in fact, have a connection to higher crime rates is important for several reasons. For those in law enforcement and related fields, this knowledge will help them prepare for the rise in violent acts that comes with a higher temperature. It can also provide a better understanding of the mental factors that contributed to the commission of a crime.

For environmentalists, the correlation between hot weather and crime is a valuable aspect of understanding the full impact of environmental changes on individuals. With the threat of global warming, temperature’s effect on crime rates becomes an even greater concern, and yet another reason to pay better attention to the environment.

Of course, temperature is just a part of the factors involved in an understanding of criminal justice and the environment, and it’s just one way that the two are connected to each other. At Virginia Wesleyan University, our online criminal justice degree and online environmental studies program are designed for students who want to explore this topic further. Our programs teach you the real-world skills you’ll need to succeed in your career, and we emphasize flexibility so that you can fit your education into your already busy life.

This article was originally published on the website of Virginia Wesleyan University and was re-posted with permission. 

Frozen flower.

Climate change will make extreme cold more prevalent — and that’s bad news for some animals

It’s important to keep in mind that climate change doesn’t mean only warmer average temperatures — it also fosters weather variability and the prevalence of extreme cold temperature events, a new paper reports.

Frozen flower.

Image credits Manfred Richter.

A team of researchers from Binghamton University investigated the effect of climate change on amphibian health and susceptibility to parasites. The researchers focused on cold weather variability, a less-discussed consequence of climate change, and discovered that it makes amphibians more susceptible to some hazards while lessening the risk of others (such as parasites). They hope the study will help showcase the important role cold weather variability, not just warmer temperatures, play in the context of climate change.

Change goes both ways

“There is a lot of misconception that global climate change only refers to an increase in warming temperatures,” says Jessica Hua, assistant professor of biological sciences at Binghamton and paper co-author. “We feel that the research in this paper is important because it highlights that global climate change is more complex than just an increase in average temperature. In fact, global climate change is also predicted to increase the prevalence of extreme cold temperature events, as well as increase the amount of variation in temperature fluctuations.”

While climate change is recognized as “one of the most serious issues facing us today,” its impact on animal and plant populations isn’t known in depth. Weather variability, in particular, can have dramatic effects on natural systems. For example, rising mean temperatures prompt organisms to breed earlier in the spring, the team explains, which paradoxically increases their risk of experiencing wild fluctuations in temperature during early development — especially cold weather.

These temperatures don’t have to fall into the ‘deadly’ range to cause damage, the team adds, to alter how susceptible amphibians are to other stressors. To investigate the issue further, they placed wood frog embryos in various cold temperature regimes, researchers looked specifically at the consequences of exposure to these lower temperatures.

Amphibians exposed to constant cold conditions as embryos were more susceptible to road salt contamination, but were able to recover as they aged, the team reports. This is particularly relevant, as salt use on roads is predicted to increase exactly as these extreme cold temperature events are taking place. The frogs exposed to cold temperatures as embryos were also smaller overall as they aged, and developed at a slower pace. This ended up protecting them against parasites as their small stature made them less attractive targets.

These results were not anticipated, the team adds, and determining whether the impact from the cold was harmful or helpful for the amphibians overall is difficult to gauge.

“We initially predicted that exposure to cold temperatures would be stressful to developing embryos. As a consequence, we expected that exposure to stressful conditions early in life would make amphibians less able to deal with other stressors later in life (i.e. parasites),” Hua said. “We were also surprised because past studies have found that cooler temperatures can increase amphibian susceptibility to another parasite (the fungus, chytrid). In this case, the negative effects of the cooler temperatures on amphibians are driven by the fact that the fungus survived better in cooler temperatures.”

Amphibian populations are on the decline globally, so considering the effects of cold temperatures may be important in understanding how to better protect them in the future, the team concludes.

The paper “The effects of different cold-temperature regimes on development, growth, and susceptibility to an abiotic and biotic stressor” has been published in the journal Ecology and Evolution.

That cold, gloomy weather you hate? It might give you a heart attack

A new study found that when the weather is cold and cloudy, more people have heart attacks.

The study was carried out in Sweden and tracked over 280,000 patients between February 2017 and April 2018 — it was the largest study of its kind, and the data is quite robust.

Weather data was available for some 274,000 patients, including mean, minimum, and maximum air temperature, wind velocity, sunshine duration, atmospheric air pressure, air humidity, snow precipitation, rain precipitation, and change in air temperature.

The researchers were looking for any patterns connecting heart attack rates with any atmospheric conditions. Results showed that lower temperature, higher wind speeds, and less sunshine are all connected with heart attack rates — but the strongest connection was with temperature.

The incidence of heart attacks was highest on days where temperatures were below 0 Celsius (32 F) and declined significantly when temperatures rose above freezing levels. Overall, a decrease from 20C to -1C (68 to 30F) was associated with a 14% increased in heart attack risk. For wind speed, an increase from 0 to 36 miles per hour, led to a 7% risk increase, while a shift from 10 hours without clouds to a fully cloudy day caused heart attack risk to go up by 11%. A few other studies have previously reported similar findings with regard to air temperature, most of these studies have been geographically limited, whereas this a nationally-wide sample (though for Sweden, which might not be representative for other parts of the globe).

Now, the more interesting question is that of causality: is the bad weather actually causing the risk, or is it a mere correlation-not-causation relationship?

David Erlinge, professor of cardiology at Lund University in Sweden and leader of the study, says that it is plausible for the cold weather to actually cause the heart attacks.

“Cold and windy weather leads to a contraction of blood vessels in the skin to conserve energy and temperature,” said Erlinge. “That increases the workload of the heart, increasing the risk of a heart attack.”

Another explanation could have a lot to do with our habits: when it’s cold outside, we’re more likely to be sick and less likely to do things which are good for our heart, like taking a walk. Perhaps it’s something to do with being indoor rather than outdoor, perhaps it’s something to do with the time of the year — while the paper does speculate on this, it doesn’t study it directly.

However, this study adds to knowledge on the role of weather as a potential trigger of myocardial infarction. Erlinge also adds that they also looked at pollution data, but surprisingly, pollution did not seem to be a relevant factor in this context.

The study has been published in JAMA.

Kent Bass Harbor.

Climate change is affecting national parks much more than the rest of the US

America’s national parks are baking — more than the rest of the country, a new study from UC Berkeley and the University of Wisconsin-Madison reports.

Kent Bass Harbor.

Bass Harbor Head Light in Acadia National Park.
Image credits NPS / Kent Miller.

Anthropic climate change is exposing the nation’s national parks to conditions that are both hotter and drier than the rest of the USA, the authors report. The paper represents the first effort to quantify the magnitude of climate change on all 417 parks in the system. According to the team, without decisive action to limit greenhouse gas emissions, many small mammals and plants that make their homes in these parks may be brought to the brink of extinction by the end of the century.

Parkticularly hot

Over the last century, average temperatures in national parks increased twice as fast as it did in all other regions of the USA; national parks also experienced the largest decrease in annual rainfall levels. Under a business-as-usual scenario, the team projects that temperatures in the most exposed national parks could increase by as much as 9° Celsius (16° Fahrenheit) by 2100.

Worryingly, this rate of change outstrips the ability of many small plant and mammal species to migrate to other lands.

“Human-caused climate change is already increasing the area burned by wildfires across the western U.S., melting glaciers in Glacier Bay National Park and shifting vegetation to higher elevations in Yosemite National Park,” said Patrick Gonzalez, the paper’s first author. “The good news is that, if we reduce our emissions […] and meet the Paris Agreement goal, we can keep the temperature increase in national parks to one-third of what it would be without any emissions reductions.”

Gonzalez is also an associate adjunct professor in the Department of Environmental Science, Policy and Management at UC Berkeley and a lead author for the Intergovernmental Panel on Climate Change (IPCC) report, a summary of the most up-to-date scientific knowledge of climate change.

The analysis included all 50 U.S. states, the District of Columbia, and four territories in the Caribbean and Pacific. The team also drew on monthly temperature and rainfall recorded by weather stations throughout the U.S. since 1895. Using this data, climate researchers created maps of the average annual temperature and rainfall totals over much of the United States.

Starting from the maps, the team calculated historical temperature and rainfall trends within the parks and over the U.S. as a whole. Temperatures in national parks increased by a little over 1° Celsius from 1895 to 2010, they report — roughly double the warming experienced by the rest of the country. Annual rainfall levels dropped by more than 12% over national parkland, compared to 3% over land in the rest of the country. Alaska and its national parks saw the most dramatic increases in temperature, while rainfall decreased most in Hawaii.

Location matters

Map national parks.

Image via Maps of World.

The team says this discrepancy is a function of where these parks are located. Many are found in deserts, high mountains, or in the Arctic region of Alaska — climates that are the hardest hit by global warming.

“National parks aren’t a random sample — they are remarkable places and many happen to be in extreme environments,” Gonzalez said. “Many are in places that are inherently more exposed to human-caused climate change.”

The team also mapped the projected future changes for both temperature and precipitation under climate models representing each of four climate change scenarios developed by the IPCC. These include a scenario where no action has been taken to reduce emissions, one that is consistent with the Paris Agreement, and two that are intermediates between these extremes.

Under the business as usual scenario, average temperatures of all the national parks (taken together) is projected to increase between 5° and 7° Celsius. The Paris Agreement scenario would limit this rise to between 1° and 3° Celsius. Temperatures would increase most in Alaska and its national parks and decrease most in the Virgin Islands and the southwestern U.S. for both scenarios.

To analyze the other two scenarios, the team “downscaled” the climate models in order to obtain more detailed maps of future climate trends within the parks. While the climate models themselves use resolutions of approximately 100 to 400 kilometers, the downscaled data have resolutions of 100 to 800 meters over most of the country. These maps can help park service employees plan for future vulnerabilities to climate change, safeguarding endangered species and other park resources by developing measures to protect against wildfires and controlling invasive species.

“The park service is already integrating this climate change information into their planning and resource management,” said Fuyao Wang, a research associate at the University of Wisconsin-Madison.

“It is important to note that even if we really do a strong mitigation of greenhouse gases, the national park system is still expected to see a 2 degree temperature change,” said John Williams, a professor of geography at the University of Wisconsin-Madison. “At this point, it is likely that the glaciers in Glacier National park will ultimately disappear, and what is Glacier National park if it doesn’t have glaciers anymore? So I think this adds weight to the importance of reducing our future levels of climate change and also extends the National Park Service mission to both adapt to these changes and educate all of us about these changes.”

The paper “Disproportionate magnitude of climate change in United States national parks” has been published in the journal Environmental Research Letters.

Man-made climate change makes heatwaves twice more likely

As large swaths of the northern hemisphere are dealing with some of the worst heatwaves in history, researchers have just published a study showing that climate change resulting from human activities makes such events twice as likely.

Man-induced climate change makes climate events much more likely, studies have consistently shown. Depicted here, the 2018 storm Eleanor.

Summers are supposed to be hot — but in many parts of the world, it’s unnaturally and unbearably hot. The UK has witnessed its driest summer in modern history, Japan reported the hottest local temperatures in recorded history, and Scandinavia, known for its frigid temperatures, has been sizzling in temperatures over 30°C (86°F).

It’s hard to draw a direct cause-effect relationship between a complex, global phenomenon and singular heatwaves — but there’s a very good chance the two are connected. In the new study, renowned climatologist Michael Mann and colleagues address this issue, looking at data from seven weather stations in Finland, Denmark, Ireland, the Netherlands, Norway, and Sweden. They chose these stations because they all had digitized records dating back to the early 1900s, unlike most other stations.

They found that, on average, man-induced climate change made heatwaves two times more likely. The results were not uniform and varied by country: in the Netherlands, Ireland, and Denmark, the odds of heatwaves have increased more than twofold.

“We found that for the weather station in the far north, in the Arctic Circle, the current heatwave is just extraordinary – unprecedented in the historical record,” said Geert Jan van Oldenborgh, at the Royal Netherlands Meteorological Institute and also part of World Weather Attribution, who worked on the study.

[panel style=”panel-default” title=”The influence of climate change” footer=””]Assessing the influence of climate change involves complex models and number crunching. Researchers attribute how often extreme events happen at a particular weather station and then compare them with modeled results of climate without the influence of human emissions of greenhouses gases (especially CO2). This way, they work out how likely climate change is to influence extreme weather events.

These studies are called attribution studies.

Attribution studies are much easier to carry out thanks to the increased processing power of modern computers, and scientists often focus on weather stations which have digitized data, which also makes the analysis easier. Such a study used to take several years, but this new analysis was made in little over a week.

Multiple lines of evidence support attribution of recent climate change to human activities, and scientists have high confidence that human activities are to blame. [/panel]

Climate scientists loath to say that an event is “caused” by climate change, but in this case, results are “unambiguous.”

“In many parts of Europe three day heat is not very exceptional and you could argue that it would be better to look at longer,” said Dr. Friederike Otto from the University of Oxford, one of the study’s authors. “But we’ve looked at longer periods and it doesn’t change the result very much.”

This is by no means a singular study — previous efforts have also consistently linked climate change with extreme weather events (both hot and cold). For instance, the heatwave in South Wales, Australia, was made at least 50 times more likely by global warming. The 2017 “Lucifer” heatwave across Europe’s Mediterranean nations was made at least 10 times more likely by climate change, and Hurricane Harvey was 3 times more likely thanks to climate change. Overall, many extreme climate events — and the increasingly hot summers — are linked with man-made climate change. A previous study from last year, also co-authored by Mann, found that all these extreme weather patterns are very likely linked to climate change. Mann actually believes this study may have understated the effects.

We are now in the phase that the effects of climate change are way beyond deniability — it’s time to start acting and tackling this problem — or suffer the consequences.

Journal Reference: Mann et al. “Influence of Anthropogenic Climate Change on Planetary Wave Resonance and Extreme Weather Events.” Sci. Rep. 7, 45242; doi: 10.1038/srep45242 (2017).

Japan experiences its hottest temperature in recorded history

Temperatures reached 41.1 degrees Celsius (106 F), as scorching temperatures killed 77 people and sent more than 30,000 people to hospitals in the country of the rising sun.

“Please be aware of heatstroke, and make sure to keep yourself hydrated and consume adequate salt,” an official said.

A sizzling heatwave has struck Japan, resulting in local records in several parts of the country, including Tokyo, where thermometers logged 40.8 degrees — almost reaching the country’s previous record of 41.0 °C, set in August 2013 in Shimanto, Kochi Prefecture. A few other prefectures also peaked over 40 °C, but the new record was set just a bit north of Tokyo, in the Saitama prefecture.

The heatwave hit right as the country was recovering from devastating floods and hundreds of landslides. Japan’s Meteorological Agency has issued repeated warnings, urging people to drink water frequently and only go in the sun if they need to, but the heat has claimed at least 77 lives, and over 30,000 people were already hospitalized due to heatstrokes. It’s not uncommon for Japan’s summers — which are notoriously hot and humid — to send people to the hospitals, but this year is particularly bad. In Tokyo, there have been 3,544 ambulance calls for heat strokes, already surpassing last year’s total of 3,454.

The heatwave also comes a mere two years before Tokyo is expected to host the Summer Olympics. Authorities have already announced they are preparing special measures to protect the athletes and spectators, like solar-blocking road paint and mobile misting stations, to make the heat more bearable.

Although it’s nigh impossible to draw a direct correlation between global and local events, there’s a mountain of science showing that global climate change can lead to more extreme climate events — both in the winter and in the summer. Heat waves are becoming more common in many parts of the world and already, a third of the planet’s population is living in an area where the daily temperatures are considered lethal more than 20 days a year.

Climate change is not one heatwave, and it’s not one hot summer — it’s a pattern of changes, but we’ve already seen these patterns unfold, from the devastating drought in California to the record-breaking temperatures in Scandinavia and Japan. Again, it’s hard to draw a direct cause-effect line between climate change and Japan’s new temperature record, but this is not an isolated case.

It’s part of a much bigger chain of events, one that’s unfolding in front of our very eyes, and that we are causing.

Curiosity mars.

Mars’ huge dust storm is now a “global” storm

The dust storm battering Opportunity is now a global storm, NASA reports.

Curiosity Mars.

Curiosity approaching Mars in December 2012.
Image credits NASA / JPL-Caltech.

Mars hasn’t been enjoying the fairest weather as of late. A massive dust storm has engulfed Perserverence Valley, pinning NASA’s Opportunity rover in place; all the dust is blocking out sunlight, preventing the bot from recharging its batteries — so much so that ground control fears it might freeze out, as its dwindling power supply can’t feed the rover’s inbuilt heaters.

According to NASA, the weather is only getting worse. The dust storm has grown in size and is inching in even on the Curiosity rover, half a Mars away from the beleaguered Opportunity. The storm has officially become a “planet-encircling” or “global” dust event.

Mars Stormborn

NASA reports that dust is rapidly and steadily settling down on Curiosity. The quantity of dust settling on the rover has more than doubled over the weekend, they note. The storm’s light-blocking factor, or “tau”, has grown to over 8.0 above Gale Crater (where Curiosity is currently rovering about) — the highest value the bot has ever recorded during its mission. For context, Opportunity is experiencing 11 tau, a value high enough to prevent its instruments from making any accurate measurements.

However, NASA is confident Curiosity will remain unaffected by the grime. Unlike its cousin, it draws power from a nuclear reactor, so the lack of light isn’t really a big issue. Curiosity’s cameras are having a hard time, however, as the lack of light means it has to use long exposure times. NASA is having it point its cameras down at the ground after each use to reduce the amount of dust blowing at its lenses.

However, there’s a silver lining. Because Curiosity can keep functioning in the storm, NASA hopes to use the rover to understand the phenomenon better. One of the main questions they want to answer is why some Martian dust storms remain small and stall before a week has passed, while others grow and grow and last for months.

“We don’t have any good idea,” said Scott D. Guzewich, an atmospheric scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, leading Curiosity’s dust storm investigation.

Together with the craft in orbit around Mars, Curiosity will collect data on the storm to help patch up our understanding.

Mars dust storm.

This animation, pieced together from pictures taken by Curiosity’s Mast Camera, shows the weather darkening over Mars. The rover is currently standing inside Gale Crater, and peeking its camera over its rim. The photos were taken over a few weeks, with the first one snapped before the storm appeared.
Image credits NASA.

The images above were taken roughly 30 kilometers (18.6 miles) away from the storm. The haze is about six to eight times thicker than what’s usual for this time of the Martian year, NASA estimates.

Dust storms on Mars are actually quite commonplace. Surprising for a dusty planet, I know. They’re especially frequent in the southern hemisphere during both spring and summer months (Mars’, not the ones on Earth). These are the months during which Mars is closest to the Sun, and the temperature imbalances in the atmosphere generate winds that mobilize dust grains (this dust is about as fine as talcum powder). Carbon dioxide ice (dry ice) embedded in the planet’s polar ice caps also evaporates during these months, making the atmosphere extra-thick — this increased pressure helps suspend dust in the air. Dust clouds have been spotted up to 60 kilometers (40 miles) high.

However, Martian dust storms don’t usually cause a ruckus. They tend to hang out in a confined area and dissipate within a week. By contrast, the current storm is bigger than North America and Russia combined, according to Guzewich. It’s even more impressive when you consider the size of Mars relative to Earth:


Mars (diameter 6790 kilometers) is only slightly more than half the size of Earth (diameter 12750 kilometers). The image shows the true relative size between the two planets.
Image credits Viking Orbiter Views of Mars, NASA SP-441, p. 14.

The size difference is one of the elements that allows Martian dust storms to grow to such immense sizes. Earth’s gravitational pull is almost double that of Mars, which helps settle the dust. Vegetation also binds the soil, preventing particles from getting airborne, and rain washes whatever gets in the atmosphere back down.

The new satellite took this full-disk snapshot of Earth’s Western Hemisphere from its checkout position at 12:00 p.m. EDT on May 20, 2018, using the Advanced Baseline Imager (ABI) instrument. Credit: NOAA/NASA.

Amazing views of Earth captured by NOAA’s latest weather satellite

The new satellite took this full-disk snapshot of Earth’s Western Hemisphere from its checkout position at 12:00 p.m. EDT on May 20, 2018, using the Advanced Baseline Imager (ABI) instrument. Credit: NOAA/NASA.

The new satellite took this full-disk snapshot of Earth’s Western Hemisphere from its checkout position at 12:00 p.m. EDT on May 20, 2018, using the Advanced Baseline Imager (ABI) instrument. Credit: NOAA/NASA.

Three months after its launch, NOAA’s newest weather satellite recently beamed back the first videos and pictures of the dear, blue marble we call home. Although the satellite is unfortunately plagued by technical difficulties that keep it from operating at its full potential, this didn’t steal any of the pictures’ charm.

The new satellite called GOES-17, joined GOES-16, another NOAA weather satellite, as a pair that scans the Western Hemisphere from the coast of Africa all the way to New Zealand. Together, the two satellites are meant to use their state-of-the-art instruments to monitor everything from droughts to hurricanes.

The ABI on GOES-17 detects smoke plumes as shown in this imagery of wildfires in central and northern Saskatchewan, Canada, observed on May 20, 2018.

The latest snapshots shown here were taken by GOES-17’s Advanced Baseline Imager (ABI), which scans Earth in 16 spectral bands, such as visible, infrared, and near-infrared channels. Infrared is particularly important since it allows scientists to image weather phenomena such as cloud formation or water vapor content even during the night when there isn’t any light reflected by the clouds.

Unfortunately, GOES-17 is going through a rough patch — it can’t keep itself cool enough for its instruments to function at full power. Among other things, this means that GOES-17 can’t employ its infrared capabilities at any time. The satellite has to actively vent off heat for the instrument to function, and infrared wavelengths can only be picked up if the sensor is below 60K (-213°C, or -350°F). Currently, the cooling system can only maintain such temperatures for 12 hours a day at best.

For today’s images, the visible spectrum was combined with ABI’s “longwave” infrared bands, which were functional during a portion of the day despite the cooling system issue. This is how these vivid, so-called ‘GeoColor’ images could be taken.

These dynamic marine stratocumulus cloud patterns off the western coast of Chile in the southeastern Pacific Ocean are revealed by the ABI.

The footage was taken on 20 May from a distance of about 22,300 miles above the equator, and publically released today on NOAA’s website. 

GOES-17 ABI captured a deck of low level stratus clouds covering the southern California coast.

The satellite is still in its testing phase and shouldn’t become fully operational until the end of this year. If the cooling system can’t be fixed by then, NOAA will look for alternative modes of operation to maximize the utility of ABI.

What is climate, why it’s not weather, and why it matters

Climate — which should not be confused with weather — represents a long-term meteorological state, the statistical average of weather taken over a meaningful period of time.

Climate should not be confused with weather. Image credits: Bryan Minear.

Talking climate

Whether it’s on the news, at our workplace, or even while having a coffee with friends, we often hear about climate — it’s a hot topic. But climate is often misunderstood and misrepresented, or simply mistaken for weather.

If we’re talking about climate, we first need to consider longer periods of time. Simply put, climate is the long-term average of weather. The standard averaging period is 30 years, but sometimes, climate is also discussed in terms of year-to-year variations. However, speaking of daily or hourly climate variations doesn’t really make much sense.

Loosely speaking, we can split it into microclimate, local or regional climate, and planetary climate. Microclimate refers to a very small or restricted area, especially when this differs from the surrounding area. We won’t focus on it here. Regional climates, on the other hand, are more interesting.

The climate of a place is affected by several factors, most importantly its latitude and altitude. Other elements such as terrain and nearby water bodies and their currents can also be important. Still, defining a local climate is no easy feat. A local climate needs to consider several different variables, the most important of them being temperature and precipitation.

With local climates being so complex, there are several widely accepted classifications, each focusing on slightly different environmental aspects. Climates are usually defined either by geographic area (ie Mediterranean) or a defining feature (ie arid). Climates can also be defined by a biome — the community of plants and animals which share similar environmental conditions (ie montane forests).

An example of a regional climate map. Image via Wikipedia.


Moving on, we can also talk about a global climate. The global climate takes the whole planet into consideration. The Intergovernmental Panel on Climate Change (IPCC), a scientific and intergovernmental body established to provide the world with a clear scientific view of the planet’s climate, defines climate as follows:

Climate in a narrow sense is usually defined as the “average weather,” or more rigorously, as the statistical description in terms of the mean and variability of relevant quantities over a period ranging from months to thousands or millions of years. The classical period is 30 years, as defined by the World Meteorological Organization (WMO). These quantities are most often surface variables such as temperature, precipitation, and wind. Climate in a wider sense is the state, including a statistical description, of the climate system.

Climate vs Weather

Weather is what annoys us, but climate is what’s posing the long-term problems. Image credits: reza shayestehpour.

Although this has been briefly mentioned above, it’s important to emphasize the difference between climate and weather. The difference between climate and weather is often summed up as “Climate is what you expect, weather is what you get.”

To put it differently, weather represents the state of the atmosphere at a particular place over a short period of time, whereas climate implies meaningful averages — the weather’s long-term, global patterns. Day and night do affect the weather, but they have no impact on climate, as they’re averaged out.

So the weatherman not forecasting tomorrow’s rain doesn’t mean we’re getting climate models wrong, they’re two different things. Weather forecasts are also based on models, but these models incorporate observations of air pressure, temperature, humidity and winds to produce the best estimate of current and future conditions. Then, the forecaster looks at the most plausible scenarios and decides what’s the most likely outcome. The forecast depends both on the model, and on the forecaster’s skill, and the forecast is only short-term. Climate models, on the other hand, rely on statistical relationships between large-scale climate events, to predict long-term developments. It can sometimes be easier to predict the long-term development of the climate than the short-term.

Different models predict different paths for our global warming.

Similarly, colder weather doesn’t necessarily mean the climate is getting colder. For instance, some parts of the US were extremely cold during the 2017-2018 winter, and yet, 2017 was one of the hottest years in recorded history. Weather is experienced locally, whereas climate refers to a wider area. It’s impossible to gauge what’s happening on a planetary scale from your local experiences alone. Weather also changes faster, while climate changes slower.

Another way to go about it is to think about weather as what you see on the window. Even if you’d look out the window every day to check the weather, you’d write it down, and after 30 years somehow made an average of it all, that still wouldn’t be the climate. Even if all the people in the world did the same thing, it still wouldn’t be the climate — because people don’t inhabit all areas of the world. We’d need people spread all around the planet, looking out the window every day, taking notes of it, and then averaging it over years or decades, to have an accurate view of what’s happening. This is why understanding climate can be so complex and confusing at times.

Thankfully, Earth-orbiting satellites and other technological advances have allowed scientists to have a good look at the broader picture, revealing clear signs of a changing climate.

Climate change

Earth’s climate is always changing; it always has, and it always will. But this doesn’t mean that all climate change is natural. Even though the climate is constantly modifying, it’s usually doing so at a much slower pace than a human lifespan. Right now, Earth’s climate is shifting at an unnaturally fast pace, and there is a mountain of scientific evidence tying that shift to human activity. But let’s take it step by step.

If we first want to talk about climate change, we need to consider what it changed from — what’s the initial state of the climate, the one we’re using to compare the current climate The World Meteorological Organization describes climate “normals” as “reference points used by climatologists to compare current climatological trends to that of the past or what is considered ‘normal’.” It does make much sense to compare today’s climate with, say, the Jurassic, 200 million years ago. Most climate scientists agree that it makes sense to consider climate change since the end of the last glacial period — which, coincidently or not, largely coincides with the start of human civilization.

Earth at the last glacial maximum of the current ice age. Based on: “Ice age terrestrial carbon changes revisited” by Thomas J. Crowley. The last glacial period occurred in the Pleistocene epoch, which began about 110,000 years ago and ended about 15,000 years ago.

Even more commonly, researchers consider the industrial revolution (1840) as a “normal,” reference point. That’s because over the past few thousand years, the climate hasn’t changed that much, and that’s when mankind started processes which can significantly affect the climate. Basically, the industrial revolution kickstarted man-made climate change.

So what’s causing climate change? For starters, there are the natural causes, such as shifts in Earth’s orbit around the Sun or in the solar energy that reaches our planet. Oceanic changes or volcanic eruptions can also play a big role. But one aspect, in particular, has proven to strongly affect climate: greenhouse gases.

Greenhouse gases absorb and emit energy within the thermal infrared range. In other words, they are a group of compounds that trap heat, making our planet much hotter than it would be otherwise.

Our atmosphere comprises of several gases. The air we breathe is roughly 78.09% nitrogen, 20.95% oxygen, 0.93% argon, 0.04% carbon dioxide, and small amounts of other gases. Although it makes up only a small percentage, carbon dioxide is a potent greenhouse gas. The concept of atmospheric CO2 increasing ground temperature was first published by a Nobel-Prize winning Swedish scientist by the name of Svante Arrhenius in 1896. Since then, the phenomenon has been widely studied, understood, and accepted. Despite what some snake oil politicians might say, we’ve known that carbon dioxide can warm the planet since before we had cars.

This is also confirmed in the long-term trends, as can be seen below.

Temperature soon follows suit after CO2. Credits: UNC Charlotte.Global temperatures are tightly related to the amount of CO2 in the atmosphere. There are other greenhouse gases in the atmosphere, and other factors impacting global temperatures (such as volcanic eruptions, which can cause a massive yet temporary temperature drop) — but in the long term, CO2 and temperature go hand in hand. This is particularly important as in the past century, a new source of CO2 has emerged: us.

The industrial revolution was powered by burning coal. The process not only generated the power to support emerging industries, but it also generated carbon dioxide. Burning coal (and subsequently oil and other hydrocarbons) is a chemical reaction which creates carbon dioxide, water, and heat. Mankind needs the heat, but the carbon dioxide comes as a mandatory side effect.

Initially, mankind didn’t think much of this. After all, the idea that something as small as burning coal could affect the entire planet seems hardly believable — even laughable. But the scale of mankind’s emissions grew year after year, becoming a force to be reckoned with.

After a while, humans learned they could also burn a much more valuable hydrocarbon: petroleum. As humans diversified their hydrocarbon portfolio, emissions continued to grow.

Towards the latter part of the 20th century, evidence started to pile up that we were, in fact, causing temperatures to rise. Here is just some of the compelling evidence that supports climate change:

  • Global temperatures are rising. Both land-based and satellite sensors are indicating that surface temperatures have increased by 2.0 degrees Fahrenheit (1.1 degrees Celsius) since the late 19th century. To make things crystal clear, 16 of the 17 warmest years on record have occurred since 2001
  • Ice sheets are shrinking overall. As expected after a temperature rise, polar ice is melting. Data from NASA’s Gravity Recovery and Climate Experiment show Greenland lost 150 to 250 cubic kilometers (36 to 60 cubic miles) of ice per year between 2002 and 2006, while Antarctica lost about 152 cubic kilometers (36 cubic miles) of ice between 2002 and 2005.
  • Sea levels are rising. Another logical consequence of rising temperatures and melting ice — global sea levels rose about 8 inches in the last century. The rate has increased dramatically in the past few decades.
  • Extreme events are becoming more and more common. While a causality between climate and extreme weather events is difficult to establish, it seems quite probable. In recent years, for instance, the US has witnessed both extreme drought and hurricanes much more than the average.
  • Flowers are blooming faster and birds have shifted their migratory seasons.
  • Ocean acidification is increasing. Often the most overlooked aspect of global warming, ocean acidification can be devastating. As some of the carbon dioxide is absorbed into the atmosphere, a part of it sinks to the oceanic water, where it makes the entire environment more acidic, with potentially devastating consequences.

Total Earth Heat Content from Church et al. (2011).

CO2 levels in the atmosphere have risen from 280 ppm (preindustrial levels) to over 400 ppm. Image credits: NASA.

This is just a part of the overwhelming evidence indicating to a global warming. Ice cores drawn from Greenland, Antarctica, and tropical areas, data from tree rings, geologic records, chemistry models — everything points to the same thing: greenhouse gases are causing climate change, and we are emitting the extra greenhouse gases.

There are literally thousands of papers concluding that climate change is happening now. A 2012 paper concluded that 13,950 peer-reviewed papers found evidence of climate change — only 24 didn’t. To make things even better, most of those were funded by fossil fuel companies.

Are we certain we’re causing climate change?

Yes, about as certain as we can be; about as certain as we rationally can be. About as certain as we are that smoking cigarettes is bad for your health — which, coincidentally or not, was also strongly denied by producers and lobby groups.

The vast (really vast) majority of climate scientists agree that we are causing climate change. We often talk about a consensus among scientists, but to some, that sounds like something people just dreamed up last night, ignoring the massive quantity of work carried out by some of the planet’s brightest minds.

For instance, the IPCC Fifth Assessment Report analyzed 9,200 peer-reviewed studies. If you’ve ever read through a peer-reviewed study, you’ll know just what a drag a single study can be, let alone thousands of them. The resulting report was over 2,000 pages long, its main conclusions being that warming of the atmosphere and ocean system is unequivocal and that it is extremely likely that human influence has been the dominant cause of observed warming since 1950. Some have demonized IPCC as a partisan group, but their conclusions fall right in line with those of researchers all around the world.

Summary of opinions from climate and earth scientists regarding climate change. Image via Wikipedia.

There have been several studies documenting existing information on climate change. In 2009, Doran et al found that 97% of climate scientists found evidence of man-made climate change. The same figure was reported by Andregg et al (2010) and Cook et al (2013). Oreskes et al found a 100% agreement within the papers they analyzed.

A group of 18 American leading scientific organizations issued a joint statement, endorsing the position. Among them were NASA, American Chemical Society, American Physical Society, The Geological Society of America, American Association for the Advancement of Science, the U.S. National Academy of Sciences. They wrote:

“Observations throughout the world make it clear that climate change is occurring, and rigorous scientific research demonstrates that the greenhouse gases emitted by human activities are the primary driver.”

Internationally, similar echoes were heard all around the scientific community. Here’s a list of other, international bodies and agencies with similar positions. Sure, you can cherry-pick a study or an organization to support your views — but it’s like with weather versus climate. No matter how much climate heats up, you’ll still have the occasional cold day.

Climate change is happening whether we like it or not, and it’s happening due to us — whether we like it or not.

For the first time in 37 years, it snowed in Sahara

An amateur photographer has captured the dry, barren, Sahara desert in an unlikely situation: covered with a white layer of snow.

The Sahara is the largest hot desert in the world (technically, the Arctic and the Antarctic are also deserts, and they’re both larger).  The average high temperature exceeds 38 to 40 °C or 100.4 to 104.0 °F and sand temperatures are even higher – though nights are much colder. However, it is a myth that the nights are cold after extremely hot days in the Sahara and overall, average temperatures range between 13 °C or 55.4 °F and 20 °C or 68.0 °F. Needless to say, precipitations are extremely scarce and snow is almost a myth. In fact, it’s only the second time in living history it snowed in the Sahara.

Amateur photographer Karim Bouchetata captured the rare phenomenon in photos, saying that the white snow looks spectacular on the bright orange dunes. The snow stayed on for almost a day, which is even more impressive.

“Everyone was stunned to see snow falling in the desert; it is such a rare occurrence,” Mr Bouchetata explained. “It looked amazing as the snow settled on the sand and made a great set of photos. The snow stayed for about a day and has now melted away.”

The last major snowfall – if you can even call it that – hit Ain Sefra in February 1979 when it snowed for a whopping 30 minutes.

Just in case you’re wondering, this isn’t a sign that global warming has slowed its course – in fact, the contrary might very well be true. At this time it’s too early to draw any conclusions.

If you want to see more photos or follow mister Bouchetata, you can do so on his Facebook page.

WMO’s “Global Climate in 2011-2015” report published, proves we need to act now

The World Meteorological Organization has just submitted a detailed climate analysis for the last 5 years (2011-2015) — the hottest years on record — and it doesn’t look very good. The WMO report “The Global Climate in 2011-2015” shows that humanity’s footprint on extreme weather and climate events is becoming more pronounced, dangerous, and costly to deal with.

Artist credits Azmaa Omassou / ZME Science / COP22.

Artist credits Asmaâ Ouassou. Photo by ZME Science / COP22.

A simple Google search and you can see a pattern emerging: we’ve consistently been reporting that this “is the warmest year” or “the warmest month on record” for quite some time now. I’d like to be able to say we were wrong at least once but, according to the WMO’s climate analysis of 2011-2015, we weren’t. It’s what we do.

The paper also shows that rising sea levels, a reduction in Arctic sea ice, continental glaciers, and snow cover in the northern hemisphere have accompanied these record-breaking temperatures.

“The effects of climate change have been consistently visible on the global scale since the 1980s: rising global temperature, both over land and in the ocean; sea-level rise; and the widespread melting of ice. It has increased the risks of extreme events such as heatwaves, drought, record rainfall and damaging floods,” said WMO Secretary-General Petteri Taalas.

The hot and unnerving

These past five years have been the warmest ever globally recorded for all continents apart from Africa — here, it was the second warmest, the paper reports. Mean temperatures over these five years were 0.57 °C (1.03 °F) above the 1961-1990 figure. For 2015, the warmest year yet, mean temperatures were 0.76 °C (1.37 °F) above the 1961–1990 average. It was also the first year when temperatures have passed the 1 °C above pre-industrial era levels mark. And it wasn’t a fluke occurrence, either — the second warmest year after 2015 was, you guessed it, 2014.

The oceans have also been feeling the heat, with mean temperatures rising to unprecedented levels. The global-average surface temperatures for 2015 were, again, the highest ever on record, followed by those in 2014. While most areas of the world recorded higher-than-average water surface temperatures, parts of the Southern Ocean and eastern South Pacific saw below-average temperatures.

Ice and snow

Arctic sea coverage also continued to decline. The mean Arctic sea-ice extent in September, averaged for 2011-2015, was 4,70 million sq km (1,82 million sq miles), 28% lower than the 1981-2010 average. For summer months, the 3,39 million sq km ice recorded in 2012 is the lowest we’ve ever seen. On the other end (pun intended) Antarctic ice extent was above the 1981-2010 average values during the timeframe, particularly during the winter maximum.

On land, things aren’t looking very well. The Greenland ice sheet experienced above-average levels of melt, with the summer months throughout the study period exceeding the melt seen in the reference years of 1981-2010. Mountain glaciers have also experienced a continued decline in volume. Snow cover extent in the northern hemisphere was “well below average” in all five years from May to August, continuing a powerful downward trend.

Sea Level Rise

Image credits Sebastian Voortman / Pexels.

Increased ocean heat accounted for roughly 40% of the observed sea-level rise in the past 60 years, the report says (as seawater heats up, it expands). The contribution of continental ice sheets to sea-level rise (through melt) is also accelerating, particularly fed by the Greenland and west Antarctica sheets.

Sattelite records from 1993 to the present show that sea levels have risen approximately 3 mm per year. In 1900-2010, this trend (measured based on tide gauges) was 1,7 mm per year — an almost 100% increase.

Freak weather

Warming climate means there’s more energy available to fuel freak weather patterns. Several individual weather and climate events were identified during 2011-2015 that were likely made more severe as a result of human-induced climate change. In the case of some extreme high-temperature events, the probability factor was increased by ten or more, the paper notes. Examples of this include the record high seasonal and annual temperatures seen in the US in 2012, or Australia and western Europe in 2013 and 2014.

In many cases, there wasn’t as much evidence to tie freak precipitation patterns to climate as for the other elements, for example, the 2011 floods in South-East Asia. But the extreme rainfalls in the UK during December 2015 were found to have been increased by as much as 40% due to climate change.

In other cases, the effect is more indirect. The 2014 drought in south-east Brazil was linked to three similar rainfall deficits on since 1940, but climate change amplified its effects by creating a substantially larger demand for water (also tied to population growth). There have also been events, such as the unusually prolonged, intense and hot dry seasons in the Amazon basin of Brazil in both 2014 and 2015, which are of concern as potential “tipping points” in the climate system.

Where does this leave us?

The report confirms (again) that what we’re seeing isn’t natural — greenhouse gas emissions power a long-term warming trend. CO2, one of the prime drivers of warming, passed the 400 parts per million (ppm) in the atmosphere mark in 2015, according to the report. The paper also examined 79 studies published in the Bulletin of the American Meteorological Society between 2011 and 2014 and found that more than half found evidence that human-caused climate change “contributed to the extreme event in question.” Some of them considered the probability of extreme heat increased by 10 times or more.

The paper also estimates, based on statistics of losses and damage provided by the UN, the cost of climate change. The East African drought in 2010-2012 led to an estimated 258,000 excess deaths, and the 2013-2015 southern African drought. Approximately 800 deaths and more than US$40 billion in economic losses were tied to flooding in South-East Asia in 2011. Heatwaves in India and Pakistan in 2015 claimed more than 4,100 lives. Hurricane Sandy, in 2012, caused economic losses totaling US$67 billion in the United States of America. The deaths of 7,800 people were associated with Typhoon Haiyan in the Philippines in 2013.

So, in a pretty precarious position. Organizations like the UN are trying to get world leaders to act on the issue — this is why we have COP’s. The agreement in Paris last year has been criticized as being too limited but, for better or worse, it has been reached and then entered into force.

But a lot of damage has already been done. Decisive action is needed, and it’s needed fast.

“The Paris Agreement aims at limiting the global temperature increase to well below 2° Celsius and pursuing efforts towards 1.5° Celsius above pre-industrial levels. This report confirms that the average temperature in 2015 had already reached the 1°C mark. We just had the hottest five-year period on record, with 2015 claiming the title of hottest individual year. Even that record is likely to be beaten in 2016,” Taalas added.

There are a lot of economic interests in play against the things being discussed and decided here, just as it happened with COP21. But as the WMO report shows, it’s time to take things seriously. This conference has been touted as “the COP of action” and hopefully, that will be the case.

The report was submitted to COP22 in a five-year timescale to allow a better understanding of climate trends and extreme events (such as prolonged droughts and recurrent heatwaves) compared to an annual report. WMO will release its provisional assessment of the state of the climate in 2016 on 14 November. The two papers will serve to inform and steer the negotiations in Marrakech.

New study might explain why winters have been more horrid in recent years

Researchers might have an explanation for why winters have gotten so horrendous, at least in areas such as the UK and the US.

Image by Jarmoluk.

Winter in the city is awful – there, I’ve said it. I mean, it’s one thing to enjoy winter in the mountains or in some remote forest with beautiful, fluffy white snow. You can just get a mug of hot cocoa or mulled wine and let it all go by. But when you’re in a city, it’s nothing like that. Everyone’s cold, everyone’s late, the traffic is awful, the snow is melting and dirty or it’s just raining. In recent years, that seems to be getting even worse, doesn’t it?

As humans, we don’t exactly have an accurate recollection of how seasons are like. We may remember an exceptionally cold or warm winter, but year after year, this kind of memories starts to get fuzzy because let’s face it – who pays that much attention to the weather anyway? Well, University of Sheffield researchers sure do. They found that the recent harsh winters were caused by the positioning of jet streams, the narrow bands of very strong winds encircling the globe several miles above ground.

“We’ve always had years with wavy and not so wavy jet stream winds, but in the last one-to-two decades the warming Arctic could well have been amplifying the effects of the wavy patterns,” Professor Edward Hanna, one of the lead researchers involved with the study, and a professor of geography at Sheffield, told Business Insider.

“This may have contributed to some recent extreme cold winter spells along the eastern seaboard of the United States, in eastern Asia, and at times over the UK.”

When the jet streams are wavy, the weather is more severe and the winter is harsher. Not only that, but the warming Arctic, which affects global circulation, also plays a part. The team believes that understanding these interactions could not only explain why we’re seeing bad winter weather, but also help perfect our forecasts so authorities can be better prepared.

“Improving our ability to predict how climate change is affecting the jet stream will help to improve our long-term prediction of winter weather in some of the most highly populated regions of the world,” Hanna said.

“The public could better prepare for severe winter weather and have access to extra crucial information that could help make live-saving and cost-saving decisions.”

Journal Reference: Nonlinear response of mid-latitude weather to the changing Arctic.

Huge waves of foam wash over Froggy Beach after last week’s storm

Stormy weather has an unusual upside if you happen to live on Australia’s eastern coasts: giant waves of sea foam. A video taken a few days after a powerful storm hit Froggy Beach shows a man enjoying this rare phenomenon.

Image via youtube

Big storms or cyclones can sometimes cause the sea to form thick layers of foam according to NOAA, similarly to what you’re used to see in a bathtub rather than in the open ocean.

The foaming is caused by winds and waves stirring the water so proteins, dead algae, and other tiny particles bind together to form longer chemical chains. Grey Leyson captured a stunning video of this phenomenon on Saturday at Froggy’s Beach near Coolangatta, Australia.

While the sea looks inviting enough like this, locals tell that people usually stay away from the ocean after storms as sea snakes have a habit of washing up on the shore.

“The biggest hazard I suppose is sea snakes, there are a lot of sea snakes that get washed in from out further,” Leyson told the Brisbane Times. “You are very unlikely to get bitten by one, but if you do, they are pretty venomous.”

This particular storm brought bigger dangers than a few sea snakes, however. It hit parts of New South Wales with a fury, causing floods and bringing very destructive surfs of over 5 meters (17 feet) on average, reaching up to 12 meters (40 feet) in height.

Thousands of people were forced to evacuate their homes and seek shelter elsewhere as the storm destroyed beachfront properties and brought heavy rains threatening the area around Narrabeen Lakes in Sydney with flooding. Four people died, and three people have been reported missing during the storm, according to the Australian Broadcasting Company.

Conditions over New South Wales and Tasmania improved by Tuesday as the storm passed.