Climate Change, Environmental Hazards

Climate Change Bringing Tropical Diseases to Higher Latitudes

Tropical diseases are spreading farther north as the climate continues to warm.
The Anopheles mosquito is responsible for the spread of malaria. Its range may be increasing due to climate change. Photo via Pixabay

It’s been known for a long time—like, since Roman times—that climate change brings disease. Roman aristocrats would move to summer homes in the mountains in order to avoid malaria-transmitting mosquitoes, for example.

But even the appearance of malaria mosquitoes was simply a summer phenomenon that was a regular part of south European climate. Nowadays, we have more to be worried about, thanks to global climate changes.

Tropical diseases like viral illness Chikungunya, West Nile Virus, and Zika; bacterial infection Vibrio vulnificus; and parasitic infection malaria are finding their way farther and farther north as greenhouse gases boost temperatures around the world.

The Asian tiger mosquito and yellow fever mosquitoes infect humans with Chikungunya. The virus had been limited to tropical regions of Africa, Asia, and South America, but as temperatures have warmed, the geographical distribution of these mosquitoes has grown. If climate change continues unchecked, a team at the University of Bayeruth warns, the virus could even spread to southern Europe and the United States.

“People have already been infected with Chikungunya in Italy, France, and Florida,” said Dr. Stephanie Thomas, a biogeography researcher at the University of Bayeruth. “However, such cases are still too rare to play any significant role in our model. The climactic potential for new diseases in southern Europe and the U.S. is probably being underestimated.”

Vibrio illnesses are caused by bacteria that occur naturally in warm ocean waters. Although Vibrio infections have been seen sporadically in warm seas from Texas to Maryland, Vibrio bacteria are spreading north. Vibrio illnesses have even appeared as far north as the Arctic Circle.

We are seeing lots of new hospitable areas opening up for these bacteria,” said Craig Baker-Austin, a Vibrio expert at the UK’s Centre for Environment, Fisheries, and Aquaculture Sciences laboratory in southern England. “Climate change is essentially driving this process, especially warming.”

In Europe, ticks that carry Lyme disease, that once only appeared in southern Europe, are now appearing as far north as Sweden. A region near Russia’s Ural Mountains has seen a 23-fold increase in tick-borne encephalitis over the past 20 years. The sand flies that host the parasite-borne illness leishmaniasis are showing up in north Texas.

“So often so many of the things we talk about with climate change are ‘this is going to be a problem in 2030 or 2050 or 2100, and it sounds so far away,” said Stanley Maloy, a microbiologist at San Diego State University. “But we’re talking about things where our one-degree centigrade change in temperature is already enough to affect infections. We have clear evidence in many cases things are happening already, and they’re tightly correlated to changes in ambient temperature, extreme weather, or water temperature.”

Regardless of whether people believe climate change is real, it’s inevitable that even the greatest skeptics will soon find themselves being affected by the spread of tropical diseases to higher latitudes.

Climate Change, Nature

Scientists Concerned About Rapid Change in Arctic River Ice

Arctic river ice is melting at an accelerating rate.

The Arctic continues to bear the brunt of climate change’s current effects, with new research showing that Arctic river ice is accruing in smaller amounts and melting earlier in the season.

Arctic groundwater comes to the surface and freezes on top of already frozen rivers, and these deposits of ice grow throughout the season until whole river valleys are covered. Some river icings have grown to over 4 square miles, and as deep as 33 feet. Traditionally, they start melting in the middle of July, which keeps many rivers running long after they would otherwise have dried up, and provides fresh water for many different creatures and habitats.

But over the past 15 years, there has been less of that ice forming, and it’s been melting about a month earlier. This means habitats that rely on that water melting later are getting less water overall, as it melts too soon and there is less of it to melt in the first place.

Looking at 147 rivers icings in the U.S. and Canadian Arctic using satellite data, Pavlesky and Zarnetske discovered that 84 of those are becoming smaller or disappearing earlier in the season. The minimum area of ice also shrank a lot during the study period. In 2000, there were 30 square miles of ice, but there were only 2 square miles in 2010. The minimum ice area has rebounded a little bit: it was up to 3 square miles in 2015.

“This is the first clear evidence that this important component of Arctic river systems—which we didn’t know was changing—is changing and it’s changing rapidly,” said lead author Tamlin Pavelsky of the University of North Carolina Chapel Hill.

The exact mechanisms of how climate change is affecting these rivers is as yet unknown, it could be that higher temperatures are directly affecting the ice, or that it is more subtly impacting groundwater, and how that water interacts with rivers.

“While glaciers tell us about climate in the mountains and sea ice tells us about sea-atmosphere interactions, the processes that control river icing may offer great insight into how groundwater and surface waters are connected in the Arctic and how our headwaters will be connected to the ocean in the future,” said study co-author Jay Zarnetske of Michigan State University.

In the meantime, these rivers and their related ecosystems are going to continue to change as the world’s overall climate warms.

Climate Change, Nature

Trees Have a Greater Impact on Climate than Previously Thought

Trees have a significant effect on the water cycle.
Trees have a significant effect on the water cycle, which aids in cooling the earth. Photo: Shutterstock

Trees are an important part of the conversation about global climate change, but according to a recent study, they haven’t been getting their dues. Much research has focused on trees as simple carbon sinks, and in general, it’s expected that they can’t offset the amount of carbon that is being out into the atmosphere. But many of those studies missed the forest for the trees, so to speak, and were looking at them from only a single viewpoint.

A recent study from the World Agroforestry Centre has compiled data from numerous other studies, from biologists, chemists, climate scientists, geologists, hydrologists, and even social scientists, and found that trees have a bigger impact that we thought. Trees have a significant impact on the water cycle, processing and redistributing water, which helps to cool the planet’s surface. Carbon sequestrations is essentially a byproduct of this.

Forests have an impact on food security and help to keep the world cooler despite rising temperatures. That will be especially important going forward, as the issue of climate change requires more than one approach. The Paris Agreement outlined both mitigation and adaptation in the future. The former means creating less pollution and increasing sequestration of carbon and other greenhouse gases where possible. The latter means finding ways to change agriculture, construction, and other human activities in ways that will work better with the changes happening to the Earth.

There is still much to be learned about how trees can help us to both mitigate and adapt to climate change, but this study is a good place to start.

“Some of the more refined details of how forests affect rainfall are still being discussed among scientists of different disciplines and backgrounds,” said Dr. David Ellison, lead author of the study. “But the direct relevance of trees and forests for protecting and intensifying the hydrologic cycle, associated cooling, and the sharing of atmospheric moisture with downwind locations is beyond reasonable doubt.”

Climate Change, Science

Snowpack Will Melt Earlier, More Slowly Due to Rising Temperatures

Snowpack will melt earlier, but more slowly, as a result of warming climate.
Snowpack will melt earlier, but more slowly, as a result of warming climate. Photo: Shutterstock

Rising global temperatures will most likely result in mountain snowpack melting earlier in the year, but at a slower rate. While that may seem confusing at first, the mechanism is pretty easy to explain. Typically, most snowpack doesn’t start melting until the summer, when the sun in strongest in that region, and then it melts quickly.

But “when snowmelt shifts earlier in the year, the snow is no longer melting under the high sun angles of late spring and early summer,” said study lead author Keith Musselman. “The Sun just isn’t providing enough energy at that time of year to drive high snowmelt rates.”

But rising temperatures will mean less snowfall generally, so there will be less snow—and that snow will be melting more slowly over a longer period. That means less danger of flashfloods in certain areas, but it can also have a number of negative impacts. For one, slower melting means less water ends up in streams because it gets soaked up by plants instead. This, in turn, means that the streams have less water, which can impact whole ecosystems, as well as urban water supplies that rely on seasonal snowmelt

“We found a decrease in the total volume of meltwater—which makes sense given that we expect there to be less snow overall in the future,” Musselman said. “But even with this decrease, we found an increase in the amount of water produced at low melt rates and, on the flip side, a decrease in the amount of water produced at high melt rates.”

The impacts could reach far beyond the immediate area affected. Reductions in melt rates could mean fewer spring floods—which would be great for infrastructure, but not so good for the ecosystems that depend on those annual floods. The meltwater will likely be warmer, which could affect trout and other fish species.

These are some significant and problematic implications, though how exactly we can deal with such problems remains to be seen. Obviously, this is another piece of evidence in favor of working to combat global climate change.

Climate Change, Conservation, Environmental Hazards, Green, Nature

Climate Change is Already Threatening Some Species

Polar bear walking near water
Climate change is affecting endangered animals even more than we might think. Image: Shutterstock

Often, when we talk about climate change, we talk about the future, about how it’s going to affect the world. But more and more, we’re realizing that it already is affecting the world, that it is no longer a “future threat” but a very real, very current problem. And part of that problem is climate change.

There are currently 873 species of mammals and 1,272 species of birds listed as threatened, but of those, only 7% of mammals and 4% of birds are considered “threatened by climate change and severe weather.” However, a recent study by researchers from the University of Queensland and the Wildlife Conservation Society has found that as much as half of those mammals and a quarter of the birds “have already responded negatively to climate change.” This means that those species, such as the mountain gorilla, will have an even greater chance of being negatively affected by future changes.

The problem is that we aren’t seeing enough studies of animals, already classified as threatened or not, that take climate change into effect.

Climate change’s effect on animals isn’t anything new to us, even if previous studies have been few and far between. Back in 2014, the UN’s Intergovernmental Panel on Climate Change was already warning us that many animals were migrating further north or south toward the water in an effort to survive catastrophic changes to their natural habitats. Only the truly flexible species will be able to make it through as habitats shift and temperatures fluctuate.

Still, these studies might not be all doom and gloom. While the threats posed to these species are very real (and likely to get worse), knowing that these problems exist allows us to start addressing them. And knowing that climate change is already negatively affecting at least some species might make it easier to motivate people to care about climate change as something that’s happening right now…something we have a chance to deter, if not stop entirely.

Climate Change, Science

A Vaccine Against Fake Climate Science News?

Scientists may have come up with a way to "vaccinate" people against fake climate science news.

For those of us who follow climate science, it’s a well known fact that 97 percent of scientists agree that human activity has had an impact on the changing global climate. But we also know that there are plenty of people who refuse to acknowledge this truth, and that they have people constantly feeding them misinformation.

Amidst the current concern over fake news sites, which present lies and opinion as facts, a team of social psychologists have come up with a striking idea: creating a “vaccine” against fake news.

Vaccines work by introducing a safe amount of a disease to a body so that the immune system learns to fight it in case it’s ever exposed to the actual virus. The idea of the fake news vaccine is similar.

The researchers surveyed a group of more than 2,000 U.S. participants across the spectrum of age, education, gender, and politics, using information about climate change. First, they asked the readers what their position on the scientific validity of climate change. They then showed the participants factual and erroneous information on scientists’ beliefs about climate change.

Two groups in the study were randomly given “vaccines” against the misinformation. There was a general inoculation in the form of a warning that “some politically motivated groups use misleading tactics to try and convince the public that there is a lot of disagreement among scientists.” A detailed inoculation picks apart the Oregon petition, an effort to discount the validity of scientific consensus on climate change, by stating that some of the signatories are fraudulent and that fewer than 1 percent of the signatories have backgrounds in climate science.

The researchers found that the inoculation caused the fake news to become less effective in swaying participants’ beliefs about the reality of climate change.

In a study of readers without the psychological vaccine, people who were shown only fake science had a 9 percent chance of coming to believe it. But people given the vaccine were much less likely to buy into fake climate science later. These results were seen across readers identifying as Democrats, Independents, and Republicans.

“What’s striking is that, on average, we found no backfire effect to inoculation messages among groups predisposed to reject climate science, they didn’t seem to retreat into conspiracy theories,” said study lead author Dr. Sander van der Linden of the University of Cambridge in England.

So what does this mean? For those who write about climate change, there is a lesson to be learned, which is that it isn’t enough to just present facts about climate change. It’s also important to discuss the misinformation, even just enough to make readers aware of anti-science trends, to help prevent them from falling for those lies.

Climate Change, Nature, Sustainability, Uncategorized

Danish Seagrass Sequesters Carbon at Record Rates

Danish seagrass sequesters carbon at record rates.
Tropical seagrass. Photo: Shutterstock

Seagrass, a type of underwater plant which flowers and grows quite like terrestrial grasses, is apparently a huge contributor to the world’s ability sequester carbon. Seagrass grows in “meadows,” large patches dominated by one or two species, which are home to many shallow-water and coastal creatures. It forms an integral part of their local ecosystems.

But seagrass also sequesters carbon dioxide at a very high rate, and in one Danish bay, it’s much better at it than anywhere else. Outside of Thurøbund, no meadow seems to hold more than 11,000 grams of carbon per square meter, but the Danish bay sequesters upwards of 27,000 grams per square meter.

Biologists think this might have something to do with the protected nature of the bay. Not protected in a legal sense, but by having less direct contact with the larger ocean. There, when the plants die, they sink to the bottom of the ocean and get buried in sediment, so the carbon they had been storing stays there. In other meadows, these plants are washed out to sea, after which nobody is sure what happens to them.

Seagrass is threatened, as are so many species on the planet. Since 1879, the Earth has lost about 29 percent of its seagrass meadows. Denmark itself has lost between 80 and 90 percent since the 1930s. But because these plants are so good at storing carbon, it’s certainly worth our time to not only find ways to preserve those meadows which still exist, but to find ways to shore them up. If we can get more seagrass to grow, returning to levels before 1879, that could be a huge help in reducing global warming.

While the Earth’s processes of naturally sequestering carbon aren’t likely to save the day, they do put in a lot of work, and finding ways to increase the effectiveness with which they do so could make quite a difference.