Tag Archives: temperatures

Seasonal temperatures influence the results of blood work

Blood tests don’t just record what’s going on inside your body — they’re also influenced by outside conditions.

Image credits Tatiana Belova.

New research comes with a surprising finding: ambient temperatures have a small, but measurable, effect on the results of medical lab work. While the findings don’t raise cause for concern, they do represent an interesting tidbit for medical personnel to consider when interpreting lab results.

Furthermore, labs could adjust to account for ambient temperatures on the day the samples were harvested using statistical methods, which would eliminate this effect from the results, according to the authors.

Outside influences

“Temperature fluctuations from one day to the next affected the results of some of the most commonly-used laboratory tests in medicine: red and white blood cells, lipids, and many others. It’s important to note that these changes were small: less than one percent differences in most tests under normal temperature conditions,” said study co-author Ziad Obermeyer of the University of California, Berkeley, in an email for ZME Science.

“Nonetheless,  we did detect effects of these changes on doctors’ medical decisions, for example, patients who had their cholesterol checked on colder days appeared to be lower-risk in terms of cardiovascular disease, and this led to a lower likelihood of being prescribed a statin.”

Together with Devin Pope of the University of Chicago, Obermeyer analyzed a dataset of lab results performed between 2009 and 2015 over several climate zones. The dataset included over four million different patients. The authors measured how changes in day-to-day temperatures affected the results, over and above the patients’ average values, and seasonal variation.

More than 90% of individual tests and 51 of 75 used in the study had been influenced by ambient temperatures, they report; these included measures of kidney function, cellular blood components, and lipids such as cholesterol and triglycerides. These day-to-day fluctuations very likely do not align with the patients’ long-term physiological trends, the team believes. For example, patients who received lipid panel checks on colder days were 10% less likely to be prescribed statins, a class of cholesterol-lowering drugs, compared to those who received the test on warm days.

“The textbook way of thinking about medical research is ‘bench to bedside’: first we come up with a hypothesis, based on theory, then we test it with data. As more and more big data comes online — like the massive dataset of lab tests we used – we can flip that process on its head: discover fascinating new patterns, and then use bench science to get to the bottom of it,” Obermeyer added for ZME Science.

“I think this ‘bedside to bench’ model is just as important as its better known cousin, because it can open up totally new questions in human physiology we haven’t dreamed of before.”

Since the study didn’t involve any experimental steps, the team could not identify the exact mechanism through which ambient temperatures influence the results of lab work. They’re looking at several possible explanations such as blood volume, specific assay performance, specimen transport, or changes in lab equipment, but they can’t yet say for sure.

“One practical implication of this study is that laboratories could statistically adjust the results they report for the ambient temperature on the test day. This could actually reduce variability by quite a bit – in fact, comparable to getting new laboratory assay technology – but at far lower cost,” Obermeyer added for ZME Science.

“There is some precedent for this: labs often use ‘middleware’ to adjust raw results (e.g., rounding low results to ‘negative’ based on reference ranges). This idea, of improving the ‘software’ rather than the ‘hardware’ of laboratory instruments, is a bit like how Tesla improved braking performance: via a software upgrade to cars’ onboard computers, as opposed to physical changes to the brakes – though of course, anything we do with patient care needs to be done with extreme care, as recent problems with Tesla’s braking software have shown.”

The paper “Variation in common laboratory test results due to ambient temperature” has been published in the journal Med.

Warming climates make hurricanes more dangerous and longer-lasting over dry land, a new study explains

Hurricanes are getting a boost from climate change and taking longer after making landfall to slow down and disperse. These changes are likely to mean that hurricanes in the future will affect communities farther inland.

Image via Pixabay.

A new study showcases how climate change is making hurricanes more dangerous and farther-reaching. Hurricanes that form above warmer waters in higher atmospheric temperatures can carry more moisture, the team explains, which allows them to keep raging stronger and for longer after reaching dry land. The problem is only going to get worse if climate change continues unabated and mean temperatures keep increasing.

Stormy futures

“The implications are very important, especially when considering policies that are put in place to cope with global warming,” said Professor Pinaki Chakraborty, senior author of the study and head of the Fluid Mechanics Unit at the Okinawa Institute of Science and Technology Graduate University (OIST).

“We know that coastal areas need to ready themselves for more intense hurricanes, but inland communities, who may not have the know-how or infrastructure to cope with such intense winds or heavy rainfall, also need to be prepared.”

The link between climate change and more powerful hurricanes is already well documented, with previous research showing that they’re becoming more intense over the open ocean. This is the first study to look at how climate change makes these storms — also known as typhoons — behave after they reach dry land.

The team looked at hurricanes in the North Atlantic that made landfall throughout the last five decades. On the first day after reaching dry land, the storms weaken roughly twice as slowly today as they did 50 years ago, the team explains.

They further explored the mechanisms behind this behavior in a series of computer simulations of four hurricanes in different sea surface temperature contexts. Once these simulated hurricanes reached Category 4 strength, the team simulated their making landfall by turning off any upwelling moisture.

“When we plotted the data, we could clearly see that the amount of time it took for a hurricane to weaken was increasing with the years. But it wasn’t a straight line — it was undulating — and we found that these ups and downs matched the same ups and downs seen in sea surface temperature,” said Lin Li, first author and PhD student in the OIST Fluid Mechanics Unit.

Li adds that hurricanes are “heat engines, just like engines in cars”, where the fuel is moisture taken up from the surface of the ocean. The heat energy it carries intensifies and sustains the storm by powering winds. Once a hurricane reaches dry land, its fuel supply is cut, meaning it will eventually decay.

Although each hurricane in the simulation made landfall at the same intensity, those that formed over warmer oceans took more time to dampen down, the team explains. All in all, they write that “warmer oceans significantly impact the rate that hurricanes decay, even when their connection with the ocean’s surface is severed”.

Additional simulations showed that the moisture stored in each hurricane explained this inertia. They start weakening as this stored moisture starts depleting. Simulated hurricanes that weren’t allowed to store moisture showed no changes in their rate of decay relative to the surface temperatures of the water they formed over.

“This shows that stored moisture is the key factor that gives each hurricane in the simulation its own unique identity,” said Li. “Hurricanes that develop over warmer oceans can take up and store more moisture, which sustains them for longer and prevents them from weakening as quickly.”

More stored moisture also makes hurricanes “wetter”, meaning they release more rainfall over the areas they reach.

The authors explain that our current models don’t take into account hurricanes’ stored humidity, making them incomplete — which is why we haven’t yet understood the relationship between sea surface temperatures and the behavior of hurricanes over dry land.

The team is now working on studying hurricanes from other areas of the world to see whether climate change is impacting hurricane decay rates across the globe.

“Overall, the implications of this work are stark. If we don’t curb global warming, landfalling hurricanes will continue to weaken more slowly,” Prof. Chakraborty concludes. “Their destruction will no longer be confined to coastal areas, causing higher levels of economic damage and costing more lives.”

The paper “Slower decay of landfalling hurricanes in a warming world” has been published in the journal Nature.

Wetter, warmer soils will intensify climate change

Climate change is poised to make tropical ecosystems wetter — which will make them release more carbon dioxide, according to a new paper.

Image via Pixabay.

The study focused on an analysis of ancient tropical soils from the submarine delta of the Ganges and Brahmaputra rivers. Throughout history, the data reveals, these soils have emitted higher levels of CO2 gas during warmer and wetter periods. The team writes that the same mechanism can amplify the effect of climate change as tropical soils today will release more CO2 into the atmosphere on top of (and due to) human emissions.

A study in the May 6th issue of Nature indicates the increase in rainfall forecast by global climate models is likely to hasten the release of carbon dioxide from tropical soils, further intensifying the climate crisis by adding to human emissions of this greenhouse gas into Earth’s atmosphere.

Worse with water

“We found that shifts toward a warmer and wetter climate in the drainage basin of the Ganges and Brahmaputra rivers over the last 18,000 years enhanced rates of soil respiration and decreased stocks of soil carbon,” says Dr. Christopher Hein of William & Mary’s Virginia Institute of Marine Science, lead author of the paper.

“This has direct implications for Earth’s future, as climate change is likely to increase rainfall in tropical regions, further accelerating respiration of soil carbon, and adding even more CO2 to the atmosphere than that directly added by humans.”

Soil respiration represents the CO2 gas released by microbes into the atmosphere as they munch on and decompose organic material at or just below the ground surface such as leaves, roots, and dead organic matter. It’s not very different, actually, from the way humans and other animals generate CO2 from cellular processes that they then breathe out.

Plant roots also contribute to soil respiration during the night when plants can’t photosynthesize, and so burn off some of the carbohydrates (sugars) they produced during the day for energy.

The team analyzed three cores collected from the ocean floor at the mouth of the Ganges and Brahmaputra rivers in Bangladesh — which form the world’s largest delta and abyssal fan with sediments eroded from the Himalayas. These cores allowed the team to track environmental changes in the region over the last 18,000 years. Their data showed that there is a strong link between soil age and runoff rates.

Younger soils, which formed during wetter epochs, showed more rapid respiration rates, while older ones — which formed in cooler, drier times — showed less respiration and held higher quantities of carbon for longer periods of time. The wetter times correlate with periods of the Indian summer monsoon, the primary source of precipitation across India, the Himalayas, and south-central Asia, was stronger. The team confirmed this link by analyzing other paleoclimatic evidence in geologic formations and fossil phytoplankton.

“Small changes in the amount of carbon stored in soils can play an outsized role in modulating atmospheric CO2 concentrations and, therefore, global climate, as soils are a primary global reservoir of this element,” Hein explains.

The team notes that soils hold an estimated 3,500 billion tons of carbon or around four times as much as the quantity of this element in the atmosphere.

The feedback process seen by the team here — where atmospheric CO2 drives global warming which increases the release of CO2 — is only one piece of a larger image. Similar findings on permafrost soils of the Arctic circle have been made in the past. There, widespread thawing is allowing for more extensive microbial activity and is responsible for an estimated 0.6 billion tons of carbon emissions to the atmosphere each year.

The paper “Millennial-scale hydroclimate control of tropical soil carbon storage,” has been published in the journal Nature.

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.

Portugal and Spain brace for record-breaking temperatures

Amid a scorching-hot summer spanning almost all of the northern hemisphere, Portugal and Spain are preparing for temperatures that could break not only the national record — but a record for the entire continent.

Forecast via Euronews.

Spain’s current record high is 47.3°C (117.14°F) and Portugal can boast a slightly-higher highest temperature, at 47.4°C. But all that may soon change, as current weather models forecast significantly higher temperatures. It’s not out of the question for Portugal to reach a groundbreaking 50°C, surpassing not only the national record but also the European record, which is currently at 48°C (recorded in Athens, Greece, in July 1977).

The probable maximum is set for Saturday, in the southern parts of Portugal and south-western parts of Spain. Met Office forecaster Sophie Yeomans says that the heatwave is directly connected to “a plume of very dry, hot air from Africa.” Although it’s unlikely for temperatures to go over 50°C, records may very well be broken, Yeomans says.

“There’s an outside chance of hitting 50C,” said Yeomans. “If somewhere gets the right conditions, it could do [it] but that’s a very low likelihood.”

Other forecasters have echoed this prognosis.

“Friday and Saturday are likely to be the hottest days with a very real chance of breaking records,” the forecaster of Meteogroup said.

The Spanish meteorology agency, AEMET, has issued an official warning of extreme temperatures, and authorities are already making emergency preparations for the dramatic heatwave. Some 11,000 firefighters and 56 aircraft have already been deployed and are on standby to tackle forest fires — that are likely to emerge in the searing heat.

Iberia, the peninsula hosting the two countries, is not the only area suffering from extreme heat. Scandinavia, an area known for its frigid temperatures, is reporting record highs, Greece is ravaged by wildfires, and most parts of France and Germany have been scorching for months. Aside from some mountainous areas and northern latitudes, few areas have been spared.

Most of Europe is under a heatwave. It’s hard to say that it’s global warming — but it sure walks and quacks like global warming.

Although it’s very difficult to assign a global trend to individual events, there is already substantial evidence that climate change is connected to these record temperatures. Recent studies have shown that man-made climate change is making heatwaves much more likely and, as was the case in previous years, it’s becoming increasingly unlikely that current temperatures and global warming are not connected.

Although record-breaking temperatures are not the norm yet, it’s becoming increasingly plausible that this will be the case in the very near future. The evidence is indicating that climate change is increasingly affecting our lives, whether we care to admit it or not.

Ozone Hole.

Ozone hole at its slimmest after 30 years of international effort, keeps shrinking

The hole in our planet’s ozone layer is getting patched up. At its peak this year, the hole grew to be two and a half times the size of the US territory, its smallest proportions since 1988 according to NASA.

Ozone Hole.

It’s blue, it’s menacing, it’s a bit tinier than last year! Hurrah for progress!
Image via NASA / Ozone Hole Watch.

Spreading up to 7,6 million square miles (19.69 million km2) at its peak this year on September 11, the hole in our atmosphere’s ozone layer seems to be healing. The hole, currently looming above Antarctica, was 1.3 million square miles (3.36 million km2) smaller than last year, the smallest it’s ever been since 1988, and it keeps shrinking.

Atmospheric sunscreen

Ozone, sometimes called trioxygen, is an allotrope (a particular structural layout) of oxygen. It’s a molecule made up of three oxygen atoms, O3, and is less chemically stable than the regular O2 molecule. Ozone is a pale-blue, toxic and quite smelly gas, but that’s ok since it breaks down into regular oxygen in the lower atmosphere. It’s also a relatively rare gas, generally formed in the upper atmosphere under the action of UV rays and the charges they generate in the lower layers of the stratosphere.

Because chemistry has a sense of humor, that same ozone layer absorbs virtually all (98% to 99%) of incoming, medium-frequency UV radiation. Awesome news if you like being alive or at least not in constant agony from radiation burns, since UV radiation can wreak havoc on organisms living on land. Exposure to higher levels of UV radiation (such as those associated with a thinned ozone layer) significantly raise the risks of developing cataract and skin cancer. Wide-scale exposure to UV levels expected in the absence of the ozone layer would drastically impact whole ecosystems at a time, and would significantly change the shape of life on Earth as we today know it.

Heavy use of ozone-damaging chemicals — in particular, clorofluorocarbons and hydrochlorofluorocarbons (CHCs and HCHCs) used in old-timey fridges and spray cans — burned a gaping hole in this layer in the 70’s and 80’s. These substances break apart in the upper atmosphere, freeing chlorine and bromine to bind with the ozone. The reactions are quicker over Antarctica (where the hole currently looms) as the frozen polar stratospheric clouds offer surfaces upon which heterogeneous chemical reactions take place.

The hole understandably had everyone quite panicked. But it’s starting to show signs of healing up.

NASA researchers believe that the increasing temperatures we’ve seen in later years helped plug the hole, as warmer bodies of air in the stratosphere help limit the rise of damaging chemicals, such as chlorine and bromine, to the ozone layer.

“The Antarctic ozone hole was exceptionally weak this year,” Paul Newman, chief scientist for Earth Sciences at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, said in a statement. “This is what we would expect to see given the weather conditions in the Antarctic stratosphere.”

This effect, however, is like the jiggling of the gas indicator while your car is running — quite tiny, and quite chaotic. The lion’s share of the progress, the draining of the gas from your car’s tank in our metaphor, can be tracked down to the year 1987 when the evidence of ozone degradation grew so worrying authorities implemented the Montreal Protocol on Substances that Deplete the Ozone Layer. Over time, the protocol grew to be an international agreement which drove massive efforts, all throughout the world, to phase out most ozone-depleting chemicals.

Almost like international agreements on threatening environmental issues are a good thing in the long run and probably shouldn’t be abandoned, right?

Paris agreement.

Hint, hint, wink, wink, America.
Seen in April at the March for Science, Washington DC. Image credits Becker1999 / Wikimedia.

The good news marks the 30th anniversary of the ozone hole’s discovery. NASA further reports that the ozone hole was at its widest in the year 2000, at 11.5 million square miles (29.78 million km2) and will likely need a further 50 years to return to its 1980s size.

Overall, very encouraging news, but one that goes to show the huge inertia Earth’s systems have in relation to change. A lesson we should take to heart as we try to grapple climate change.

We can expect more and more extremely hot days if we don’t take drastic climate action

According to a new analysis from the Climate Impact Lab, even if we take moderate (but not drastic) climate action, we can expect more and more hot days in the years to come.

Hot days are more than a nuisance. When they hit, they hit agriculture, water security, and our health. Heat waves killing people is more than a rarity, claiming thousands of lives each year. As you’d expect from a phenomenon called ‘global warming,’ the planet is about to get even hotter.

Naturally, extreme heat especially threatens the areas close to the Equator — Northern Africa, Arabia, and India are already experiencing dramatic heat-related events, but they’re not the only ones. As you’d expect, Australia and South America are also facing numerous hot days, as is the Middle East, Southern Africa, and much of South-East Asia. But while Europe is mostly spared from this, the same can’t be said about the US.

Ironically, the country which has pledged to back away from the Paris Agreement will be among those who will suffer the most from increasing temperatures. While the North and central parts are mostly safe, the Southern US, as well as both coasts, will experience more and more torrid days.

Again, this is set to happen even if some climate action is taken — broadly, in accordance with the Paris Agreement. So then, you might wonder, why bother at all? Well, if we don’t do anything, it’s gonna be even worse; much worse.

Under that scenario, Washington could swelter in 95-degree weather for 74 days a year, as would much of the US. Virtually no area will be spared of heat days if this happens.

“Right now, when you start talking to people about higher temperatures, they tend to think, great, more beach days,” said Solomon Hsiang, a professor of public policy at the University of California, Berkeley who helps direct the lab.

“What’s often less appreciated is just how much an extremely hot day can distort our lives in all sorts of ways we don’t often even think about.”

Thankfully, the world is moving away from this scenario, as most countries are taking concrete steps towards limiting their greenhouse gas emissions. In other words, we’re not really headed for the worst case scenario, but we’re also not headed for a good scenario. In a way, this sums up the Paris Agreement and its importance pretty well.

It is by no means a perfect agreement. It is ambitious but again, by no means is it a pinnacle of ambition. Its purpose is basically to ensure that the world doesn’t go to hell — it’s a starting point. It can be improved, it can be finessed, but it’s a planetary agreement that stuck; everyone agreed to it, except for Syria (who is in a civil war) and Nicaragua (who thus protested it’s not ambitious enough). Trump’s announcement to withdraw from the pact could add the US to that very short list.

Taking a look at the ‘little ice age’ of 1810

ice-ageGlobal warming is one of the main concerns on everybody’s lips, causing more and more damage to the environment every year, sometimes in ways that seem hard to believe; everyday there seems to be a new report about something that went, is going, or will be going terribly wrong. However, in the early 1800s, the situation was in diametric contradiction with everybody being worried about a global cooling that seemed to come out of nowhere.

It all peaked in 1816, when in most places of the world there was actually no summer at all ! That year’s chill was blamed by climatologists on the eruption of the Indonesian volcano called Tambora, but why the few years before 1816 were also way colder than usually remained a mystery. However, newly uncovered evidence from the ice of Antarctica and Greenland suggests that another volcanic eruption was probably responsible for it.

Jihong Cole-Dai, a chemistry professor at South Dakota State University led the expeditions that cleared this intriguing question that seemed to be without an answer. He found evidence of another eruption some 6 years before the 1815 one (which was responsible for the 1816 cooling). Here’s why major volcano eruptions have such a big influence:  they practically dump immense quantities of sulfur dioxide and ash that act pretty much like an umbrella, shading the Earth and reflecting sunlight for several years.

However, it’s obvious that a single volcanic eruption couldn’t be responsible for ‘freezing’ a whole decade. Cole-Dai and his team found evidence of one more eruption that helped trigger the mini ice age. However, they weren’t able to pinpoint the volcano, saying that they only know it has to be somewhere close to the equator and really big. I don’t know for sure but I’m guessing that a more detailed analysis will give some more clues regarding this volcano and researchers will be able to find it, despite the fact that it seems to be a ‘needle in the haystack’ kind of search.

Satellites Confirm Half-Century of West Antarctic Warming

Antarctica Global Warming

Temperature variation in Antarctica; red means hotter

Despite whatever you may hear, it’s obvious that we still don’t have a clear understanding of the impact we’re having on the planet we call home; there are studies that show we’re totally destroying it, and there are studies that we’re an ant on a mountain, so it’s really hard to say for sure how much damage we cause. We do cause damage, it’s just about the significance of the damage we are causing.

The Antarctic Peninsula provides very valuable clues regarding those aspects, as it’s a pretty good meter of what’s going on with worldwide climate, and despite the fact that a portion of it has been somewhat instable, most of it didn’t suffer from significate temperature changes. But recent studies confirmed what numerous scientists suspected to be true:

“Everyone knows it has been warming on the Antarctic Peninsula, where there are lots of weather stations collecting data,” said Eric Steig, a climate researcher at the University of Washington in Seattle, and lead author of the study. “Our analysis told us that it is also warming in West Antarctica.”

Scientists came to this conclusion after analyzing results from historical temperature data from ground-based weather stations and also results from more recent times. They tried to gather as much data as possible to fill in the gaps, and they pretty much managed to do that; they used a statistical technique to fill in whatever gaps still remained.

The conclusions were pretty dire. The Antarctic temperature has increased by about 0.12 Celsius degrees per decade. The whole area is very vulnerable to climate shifts, especially the west side, and if the West Antarctic sheet temperature goes below freezing, the sea levels will rise with about 6 meters.