The most abundant greenhouse gases in the Earth’s atmosphere are carbon dioxide (or simply carbon), methane, nitrous oxide, ozone, and chlorofluorocarbons. We now know that carbon stays in the atmosphere between 300 and 1000 years (!).
Greenhouse gas concentrations are dependent on the balance between the “sources” and “sinks” (forests, wetlands, etc) that function to create and destroy these gases respectively. Anthropogenic (human-related) activities increase these concentrations by releasing amounts of gases into the air on one hand and intervening with (ie removing) the sinks on the other hand. Some facts about GHG:
- Since the industrial revolution, the levels of greenhouse gases in the atmosphere have increased disproportionally and are still increasing today, despite great efforts (and even greater intentions) to reduce. Alarmingly, the increase has resulted in a so-called radiative-forcing effect where heat is trapped inside the Earth’s atmosphere, thereby contributing to the increase in global temperature. Changes in the Earth’s temperature will trigger other phenomena like changes in wind patterns and variation of cloud covers.
- Every tenth of a degree that the earth gets warmer, leads to more extreme weather catastrophes. We are currently sitting at 1.1°C warmer than pre-industrial levels and scientists have warned that we must stay well below 2°C, ideally 1.5°C in order to preserve a livable climate. However, if we keep emitting carbon at the current level, we are likely to heat the planet to 2.7°C by 2050 and beyond. This is a climate humans and many other species cannot survive in.
- The increase in the amount of carbon dioxide (CO2) accounts for more than half of global warming, compared with other gases like methane (CH4), nitrous oxide (NO), ozone (O3), and chlorofluorocarbons (CFCs) which account for 16%, 5%, 12%, and 12% respectively.
- We now know that carbon stays in the atmosphere at least 300 years. Methods to reduce the emission of greenhouse gases won’t decrease the impacts of climate change rapidly, which is why we must act now to change our course towards a warming of 2.7°C.
(partially from www.Bioexplorer.net)
Detailed information on how our future might look like on a warmer planet gives the 2021 report on Climate Change by the IPCC.
Would you like to know what live in NZ will look like on a warmer planet? Read the NZ Climate Change Risk Assessment 2021.