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.”

Advertisements
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.

Climate Change, Nature, ocean

Cephalopod Populations Grow in Warming Oceans and Threaten Ecological Balance

Giant Australian Cuttlefish are one of the cephalopod species experiencing population growth due to an increase in ocean temperatures caused by global warming.
Giant Australian Cuttlefish are one of the cephalopod species experiencing population growth due to an increase in ocean temperatures caused by global warming. Photo: Eureka Alert | Scott Portelli, Wildlife Photographer.

By now, we’re all used to reading stories about how global climate change is harming life on Earth. This increase in temperature is a big problem for the world’s oceans.

Rising water temperatures are displacing species and leading to coral bleaching. It’s not all bad news. There are some creatures who are benefiting from climate change.

Cephalopods, which include octopi, squid, and cuttlefish, have been on the rise over the last sixty years. Although nobody is sure why this is happening, between 1953 and 2013, the population of 35 different species has been increasing.

Cephalopods grow quickly, they don’t live very long, and they are very sensitive to environmental change, making them quite adaptable. This explains their rapid expansion in numbers.

Whether warming oceans are entirely responsible is unknown, but it’s not likely to be that simple. Ecology is complex, and there are probably a number of factors at work in this population growth.

Another question is how this rise in population will impact other creatures that share ecosystems with these cephalopods. Cephalopods are voracious predators. Larger populations of them could devastate their prey species and related species before the new population reaches an ecological balance.

Cephalopods aren’t apex predators there are other creatures who prey on them. Their larger numbers might provide a surplus of prey for sharks and other creatures. Humans could be encouraged to harvest more of them without damaging their populations. Though making business decisions on something that might be a quirk can be risky.

More research needs to be done to understand this population shift. How strongly are these population growths tied to global temperature and human activity?

Will they continue to change in proportion to the global temperature, and how will efforts to reduce climate change impact them? Luckily scientists all over the world are investigating these issues.

Conservation, Nature, Science

There Are More Unique Species on Earth that We Thought

Soils are one of the largest reservoirs of microbial diversity on Earth. It is not uncommon for a gram of soil to contain 1 trillion cells and 10,000 species of bacteria, including Actinomyces israelii (pictured). |
Soils are one of the largest reservoirs of microbial diversity on Earth. It is not uncommon for a gram of soil to contain 1 trillion cells and 10,000 species of bacteria, including Actinomyces israelii (pictured). | Photo: GrahamColm | WikipediaCC.

If you follow science news at all, you’ve likely read about the discovery of countless new species. It seems like nearly every day a scientist somewhere is describing a new form of life that we didn’t know.

Consider microbial organisms, i.e. anything too small to be seen by the naked eye. Those little things are everywhere, with a single gram of soil containing up to a billion such life forms.

So we keep finding new life, but that has to stop eventually, right? According to a study from Indiana University, it’s more likely that we will never successfully catalog all the life on Earth.

Why? Not for lack of trying, but that study estimates that there are about one trillion unique species on Earth. How many have we found so far? Only one thousandth of one percent, meaning 99.999% of organisms out there is a total mystery.

Those are some staggering numbers, and like the best science, in trying to answer a question, these researchers found out just how little we know. The study reviewed other studies on biodiversity. Over 35,000 recorded sampling efforts of everything from trees to bacteria.

Earlier estimates assumed a much lower number of unique species, but they have routinely used sample sizes that were too small and sometimes suspect math. There also haven’t been many efforts to look at these samplings in the larger context and ask the big questions about biodiversity.

So what does all this mean? Well for one it means that scientists who study microbial life will never want for something to do, which is a nice bit of job security.

But it also gives us an idea of just how diverse life on the planet is, and why protecting it is so important because it’s not as if every single species is represented everywhere.

Climate Change, Science

Glacial Melt and Erosion Leads to More Volcanic Activity

U-shaped valley in Leh Valley, Ladakh, NW Indian Himalaya. The glacier visible at the head of the valley is the last remnants of the formerly much more extensive valley glacier, which carved this valley.
U-shaped valley in Leh Valley, Ladakh, NW Indian Himalaya. The glacier visible at the head of the valley is the last remnants of the formerly much more extensive valley glacier, which carved this valley. Photo: Dan Hobley | WikiMedia.

According to a recent study by researchers at the University of Cambridge, we’ve been underestimating the CO2 levels at the end of the last ice age. It turns out that melting glaciers lead to an increase in volcanic activity, something they have known about for a while, but so does increased erosion, a side effect of that melting which they hadn’t thought of before.

Melting glaciers reduce pressure on the Earth’s mantle, allowing for greater magma production and more volcanic eruptions. That’s because rocks under less pressure melt at lower temperatures. Erosion contributes to this as well, as parts of the Earth’s crust change in depth; those regions put less pressure on the mantle.

And of course, increased volcanic activity unleashes more CO2 into the atmosphere, which results in more melting, and so on. It is this system, which brings an end to an ice age, a process that generally lasts about 20,000 years or so. Glacial and interglacial periods (we’re in the latter now) tend to last in 100,000-year cycles.

Because the timescales are so vastly different, the researchers warned readers not to draw too strong a connection between these systems and the glacial melting that were seeing now as side effect of human activity. Global warming is leading to increased glacial melt, and increased erosion, both form those glaciers and in other ways as well.

That could mean that, as time goes by, we will see an increase in volcanic activity around the world, which could have a lot of negative consequences. For one, that means more CO2 in the atmosphere, but it also means the potential for massive destruction and huge loss of life, depending on the activity in question. If the rebuilding effort afterward leads to greener communities moving forward, it may help offset some of the damage, but at what cost?

Climate Change, Nature, Science

Icebergs Are Essential to Fighting Global Warming

Surrounded by ice, bright green phytoplankton bloom in open water areas—called polynyas—in the Ross Sea during Antarctica’s spring and summer.
Surrounded by ice, bright green phytoplankton bloom in open water areas—called polynyas—in the Ross Sea during Antarctica’s spring and summer. Photo: NASA Earth Observatory | FlickrCC.

According to the University of Sheffield, icebergs in the Southern Ocean have a pretty big impact on how much carbon is sequestered in those waters.  Runoff from the icebergs is rich in nutrients, and helps phytoplankton grow. Phytoplankton work like plants, and so they breathe in carbon in the air and contribute to keeping that carbon from getting trapped in the atmosphere and contributing to global warming. The Southern Ocean is responsible for about 10% of oceanic carbon sequestration.

The researchers looked at satellite imagery of the oceans color, an easy way to determine phytoplankton activity, taken between 2003 and 2013. They focused on icebergs that were at least 19 kilometers long (about 11 miles, almost as long as Manhattan Island), which could leave trails of fertile water hundreds of kilometers long. All told, it looks like icebergs are responsible for about 20% of the total carbon sequestered in the Southern Ocean.

Now for the bad news—icebergs have been calving or breaking into smaller units, more rapidly in recent years, because global warming has been increasing average ocean temperatures. With more miniature icebergs, there will be fewer phytoplankton blooms, meaning less carbon gets sequestered and more carbon enters the atmosphere. More carbon in the atmosphere means more global warming, higher water temperatures, and fewer icebergs.

While icebergs have contributed to carbon sequestration for much longer than humans have been around, there’s already more carbon in the atmosphere than they handle. That means we’re looking at a downward spiral. This change will happen gradually, of course, but we’re already getting pretty close to the point of no return as far as climate change is concerned. While this new information about icebergs and their relationship with carbon sequestration is fascinating, it also serves to point out another problem we need to fix.

Climate Change, Science, Uncategorized

The Earth Entered A New Climate Regime In The Late 1980’s

A high-altitude aerial oblique view taken on November 4, 1982 shows the effect of the El Chichón eruption about seven months later. This view from the west shows fumaroles around the new lake partially filling the crater and areas devastated by pyroclastic flows and surges. The circular rim of the nearly 2-km-wide pre-eruption somma can be seen surrounding the 1982 crater rim.
A high-altitude aerial oblique view taken on November 4, 1982 shows the effect of the El Chichón eruption about seven months later. This view from the west shows fumaroles around the new lake partially filling the crater and areas devastated by pyroclastic flows and surges. The circular rim of the nearly 2-km-wide pre-eruption somma can be seen surrounding the 1982 crater rim. Photo: NASA.

Countless studies have shown that humans are responsible for global warming, a phenomenon referred to as anthropogenic warming. According to a new study by researchers at Plymouth University, natural events like volcanic eruptions can also contribute to that warming. In fact, the El Chichón volcano in Mexico, which erupted in 1982, was such a significant contributor that it helped anthropogenic warming perform the largest shift in global climate in 1,000 years.

According to the paper, the Earth is now under a different “climate regime” than it was beforehand, a shift which is centered on the year 1987. The effects have been far ranging, and we’re still seeing them today. These include “a 60% increase in winter river flow into the Baltic Sea,” and a “400% increase in the average duration of wildfires in the Western United States.” Considering how bad, and far-reaching, wildfires were this year; it’s easy to see why this shift isn’t a good thing.

The research also sheds light on the process of global warming itself. That process isn’t a purely gradual one, but features sudden increases. Anthropogenic warming is primarily caused by carbon emissions, produced by burning fossil fuels, which tends to be relatively stable, although the specific amounts vary from year to year and place to place. With the addition of things like volcanic eruptions, however, the damage caused by the gradual build up of carbon emissions can get a pretty big boost.

Volcanic eruptions are, of course, outside of our control, and obviously not our fault. But it’s important to remember that they are pretty rare, and even at the most volcanically active points in the Earth’s history, it took an incredibly long time, and a lot of eruptions, to affect significant change to the world. With humans laying the groundwork though, even one eruption is capable of triggering severe changes.