Climate change caused by humans has a huge impact on the Amazon rainforest and the last glaciers that abated after melting, as new NASA data highlights the potentially catastrophic rising temperatures affecting the Earth. Although observations of possible events related to climate change have been going on for several years now, new results paint a clear picture of how some of the largest ecosystems on the planet are struggling.
In the Amazon rainforest, drying out is the problem. A study by scientists at NASA's Jet Propulsion Laboratory in Pasadena, California analyzed decades of ground and satellite data and tracked moisture levels.
"We observed that during the past two decades there has been a significant increase in dryness in the atmosphere as well as in the atmospheric demand for water above the rainforest," explains Armineh Barkhordarian, lead author of the study and researcher at JPL. The results indicate that elevated levels of greenhouse gases account for about half of the wave in dry conditions. It has left the rain forest noticeably dryer.
It becomes a problem when you consider that the Amazon rainforest acts as a huge CO2 processing plant. Its trees literally absorb billions of tons of gas each year, a process that helps keep the temperature of the earth down. Dryer conditions, however, mean the rain that the trees require to drive photosynthesis in shorter supply, leading to conditions where the forest cannot sustain itself.
According to the researchers, while half of the blame can be put on rising greenhouse gases, that does not mean that people are not on the hook for the rest. "When we compare this trend with data from models that estimate climate variability over thousands of years, we determined that the change in atmospheric aridity is far beyond what would be expected from natural climate variability," says Barkhordarian.
Human activity, especially the clearing of forest areas so that they can be used for agricultural purposes such as crops and animals grazing, is a significant risk, it is suggested. The most significant and systematic drying of the atmosphere was observed in the southeastern region of the rainforest, and this is where deforestation is most active. Episodic drying has been observed elsewhere, but in areas where there would normally be no dry season. If it is not controlled, the rainforest can simply begin to shrink and die without leaving any natural way to handle the large amount of carbon dioxide released into the atmosphere.
Meanwhile, other NASA data on shrinkage in ice has been identified. Again, this is nothing new, except that Taku Glacier – just north of Juneau, Alaska – has shown no signs of retreating so far. According to Nichols College glaciologist Mauri Pelto, it is the last remaining glacier that can withstand melting – or at least it was.
Using images captured by NASA's Operational Land Imager on Landsat 8, changes in the boundaries between Taku Glacier and the river have been identified. At 4,860 feet from surface to bed, Taku is one of the thickest known alpine glaciers in the world. It was also, until about 1988, actually winning mass and advancing.
From 1989, however, the thickening drew significantly. From 2018, Taku began to retreat – coinciding, Pelto points out, with Alaska recording summer temperatures.
"Being able to make the transition happen so quickly indicates that the climate is overriding the natural cycle of progress and retreat that the glacier would normally go through," concludes Pelto. "Taku Glacier is not exposed to melting it sooner, which will drive new changes."
Some of these changes may have an impact on their impact on life on earth. Earlier this year, researchers predicted that if climate change cannot be controlled, it could lead to a sea level of 6.5 meters by 2100.