Human activity and our climate are undoubtedly linked. As a matter of fact, the Intergovernmental Panel on Climate Change, in their 5th assessment report, explained that they are 95% confident that humans play a significant role in climate change. There are many factors that contribute to this statistic, but the primary problems that tend to be the subject of policy reforms are greenhouse gasses and environmental degradation.
Greenhouse Gasses
Greenhouse gasses are essentially gasses that prevent heat from escaping the planet. As more of these gasses are released into our atmosphere, whether through natural causes or through human activity, it becomes more difficult for heat to escape our planet, which contributes to rising temperatures. The problem with greenhouse gasses is that many gasses, such as carbon dioxide, are long-lived gasses, meaning that they don’t respond physically or chemically to changes, making them semi-permanent. As a result, greenhouse gas emissions are a compounding issue.
Here are a few important greenhouse gasses:
Carbon dioxide. Carbon dioxide accounts for roughly 76% of global greenhouse gas emissions, making it one of the most talked about byproducts of industry. In 2015, human activities emitted 40 billion metric tons of carbon dioxide. For context, volcanoes, which are an example of natural emissions when they erupt, emit roughly .6 billion metric tons. The most prominent industry behind carbon dioxide emissions is the energy sector.
Methane. Although less prevalent in our atmosphere compared to carbon dioxide, methane, over a 20 year period, can trap 84 times more heat per mass unit. It is believed that human activity is behind 60% of methane emissions. The agriculture and energy sectors are some of the biggest contributors of methane emissions.
Nitrous Oxide. Nearly 300 times more potent than carbon dioxide, nitrous oxide can remain in our atmosphere for 114 years, on average, while damaging our ozone layer. About 40% of nitrous oxide comes from human activities, and in the U.S., 75% of nitrous oxide emissions from human activity are a result of agricultural activity.
Water vapor. As the Earth’s atmosphere becomes warmer, water vapor becomes more abundant, increasing the probability of clouds and precipitation. This makes water vapor an important feedback mechanism for analyzing global warming.
Environmental degradation
Environmental degradation, specifically land degradation, is another key driver in climate change. In the status quo, less than roughly 25% of Earth’s land surface has not been subjected to substantial human activity and its impacts; by 2050, it is expected for that estimated value to fall to less than 10%. Detrimental actions such as deforestation, which contributes 10% to the total human-induced greenhouse gasses, and unsustainable agriculture, not only produce emissions, but also devastate the very entities that can reduce the impacts of said emissions.
Here are a few important carbon sinks that are being impaired by human activity:
Soil. There is more than 2,500 billion tons of carbon in our soil, meaning that more carbon lies in our soil than in our atmosphere and plant life combined. However, the world’s cultivated soils have already lost between 50 to 70 percent of their original carbon supply, much of which has turned to carbon dioxide after exposure to air. As land degradation continues, more carbon will be released, turning into the carbon dioxide that perpetuates global warming.
Plants. 19% of the world's carbon is stored in plants. But as a result of human activity, plant life may no longer be a reliable carbon sink. From 2003 to 2014, tropical forests had a net carbon loss of 425 million tons; as a result land degradation and disturbances, tropical forests have lost 69% of their carbon stock. Again, this only perpetuates global warming as carbon turns into a greenhouse gas.
Because of environmental degradation, our carbon sinks are turning into carbon emitters.
The current trend of human activity has had a detrimental effect on our environment and has exacerbated climate change. But why hasn’t anything been done to curb these impacts? Find out in the next installment.
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