Just half a degree matters a lot when it comes to global warming. Scientists have taken a closer look at the difference between 1.5 degrees Celsius and 2 degrees Celsius and found that the two temperatures result in drastically different impacts.
In this latest study, a team of researchers looked at a number of hot spots around the globe where projected climate impacts at 2 degrees are significantly more severe than at 1.5 degrees. One of these areas, in particular, is the Mediterranean region. Here, there are already climate impacts. Though with a global temperature rise of 1.5 degrees, the area is expected to have 10 percent less fresh water than in the late 20th century. With a rise of 2 degrees, this will double to be 20 percent less.
"We found significant differences for all the impacts we considered," said Carl Schleussner, lead author of the new study and scientific advisor at Climate Analytics in Germany. "We analyzed the climate models used in the [Intergovernmental Panel on Climate Change (IPCC)] Fifth Assessment Report, focusing on the project impacts at 1.5 degrees Celsius and 2 degrees Celsius warming at the regional level. We considered 11 different indicators, including extreme weather events, water availability, crop yields, coral reef degradation and sea-level rise."
Tropical regions are expected to experience the most impacts from warming temperatures. With that said, warm spells are expected to last up to 50 percent longer with a two-degree warming trend as opposed to a 1.5-degree warming trend. This warming could greatly impact tropical coral reefs. This means limiting the warming could be the difference between putting these ecosystems at risk of severe degradation or their survival.
"Some researchers have argued that there is little difference in climate change impacts between 1.5 degrees Celsius and 2 degrees Celsius," said Jacob Schewe of the Potsdam Institute for Climate Impact Research in Germany. "Indeed, it is necessary to account for natural variability, model uncertainties and other factors that can obscure the picture. We did that in our study, and by focusing on key indicators at the regional level, we clearly show that there are significant differences in impacts between 1.5 degrees Celsius and 2 degrees Celsius."
The findings were published in the April edition of the journal Earth System Dynamics.