In early October, the Intergovernmental Panel on Climate Change (IPCC) got the world's attention with a new report, outlining what may happen if the Earth heats up just a few degrees. Every passing year of inaction jeopardizes life on the planet. For the IPCC that means that keeping temperature increases in check is key to slowing down the ravages of climate change.
The main goal of the Paris Agreement, the treaty designed to foster an international consensus on combating climate change, is to keep global temperatures from rising any more than 2 degrees Celsius above pre-industrial levels.
Human-induced global warming is no longer an “if.” The more ambitious goal is to keep future increases under 1.5 degrees Celsius since that small increase means the impacts of global warming on land, water, and humans will be much worse as temperatures continue to increase. In 2017, the Earth had already experienced a 1-degree Celsius increase above pre-industrial levels.
The process, which slowly accelerated during the Industrial Revolution, leading to increases in carbon dioxide and other greenhouse gases in the atmosphere, has contributed to warmer ocean water temperatures. Marine aquaculture and fisheries are already suffering as a result of the carbon dioxide that the ocean has absorbed, resulting in ocean acidification.
At this pace, the Earth will become 1.5 degrees warmer between the years 2030 and 2052. In order to keep warming below 1.5 degrees Celsius, carbon dioxide levels need to decline by 45 percent from 2010 levels by 2030 to reach “net zero,” when carbon dioxide emissions are non-existent or balanced out by other natural factors, such as forest carbon sinks (places in the natural environment where more carbon is stored than released).
Warmer water temperatures and acidification inhibit shell development in shrimp, oysters, corals, and some species of zooplankton—the base of the marine food chain. Some ocean species such as bass, salmon, and shad will relocate to cooler waters earlier in the year to beat the heat.
But some species like kelp and coral, which can't migrate, will die out. Additionally, as ocean temperatures increase and the seas rise in places like the Arctic, there is a chance that those waters will be free of ice one out of every 100 summers. (If temperature increases reach 2 degrees Celsius, the chances increase to one out of every ten summers.)
Risks to health, food security, water supplies, and economic growth are projected to increase. If adaptation and mitigation efforts do not come into play in the meantime, human mortality rates from climate events like heat waves will rise. Indigenous people, the poor, and people who depend on agriculture and coastal livelihoods like fishing or tourism also will be affected.
In order to keep temperatures in check, the IPCC proposes governments work together immediately and quickly. Some regions have already implemented plans to lower greenhouse gases, but those are still not enough.
There is no definitive way to keep warming increases below 1.5 degrees Celsius, but shifting to renewable energy sources; making diet changes, such as moving away from land-intensive animal meat production; utilizing green infrastructure, such as green roofs; and implementing smart urban planning strategies could help. It's going to take a lot of international effort to control global warming—and it's going to need to happen quickly.
