While world leaders are discussing how to keep climate change within 2 degrees Celsius (2C) above pre-industrial, it’s important to note that even the climate change we have already caused is having a massive impact on the planet. According to a new University of Florida study, global warming has already affected every aspect of life on Earth, from genes to entire ecosystems.

Global oceanic and terrestrial phototroph abundance, from September 1997 to August 2000. Image credits: NASA/GODDARD.

Climate change impacts have now been documented across every ecosystem on Earth, despite an average warming of only ~1°C so far, the study argues. While localized effects and consequences have been described numerous times, global damage estimates remain rare. This paper, which recently appeared in the journal Science, is the result of an international collaboration featuring researchers from 10 countries, led by Brett Scheffers.

“We now have evidence that, with only a ~1 degree Celsius of warming globally, major impacts are already being felt in natural systems,” said study lead author Brett Scheffers, an assistant professor in the department of wildlife, ecology and conservation in UF’s Institute of Food and Agricultural Sciences. “Genes are changing, species’ physiology and physical features such as body size are changing, species are shifting their ranges and we see clear signs of entire ecosystems under stress, all in response to changes in climate on land and in the ocean.”

For humans, the impacts are more and more unpredictable, and more and more dramatic. They range from increased pests and disease outbreaks to reduced productivity in fisheries, and decreasing agriculture yields. But as these impacts are exacerbated, the environmental services that wildlife provides will also be dramatically affected. The sheer level of change is stunning, as co-author James Watson from the Wildlife Conservation Society and University of Queensland notes:

“The level of change we have observed is quite astonishing considering we have only experienced a relatively small amount of climate change to date. It is no longer sensible to consider this a concern for the future. Policy makers and politicians must accept that if we don’t curb greenhouse gas emissions, an environmental catastrophe is likely.”

He added that for some people, this level of change came as a surprise.

“Some people didn’t expect this level of change for decades” said Watson. “The impacts of climate change are being felt with no ecosystem on Earth being spared.“

But just as worrying, researchers report that change is also taking place at a genetic level.

“In addition to the more easily observed changes, such as shifts in flowering phenology, we argue that many hidden dynamics, such as genetic changes, are also taking place.”

The Paris agreement, which has recently entered into force, is an agreement to limit global warming to 2C. The agreement does feature a more ambitious goal at 1.5C, which can be aimed at if possible. But even at 1C, we’re seeing dramatic results. What will happen over that is still notclear.

“Current global climate change agreements aim to limit warming to 1.5 degrees Celsius,” said Wendy Foden, co-author and chair of the IUCN Species Survival Commission’s Climate Change Specialist Group. “We’re showing that there are already broad and serious impacts from climate change right across biological systems.“

Journal Reference: James E. M. Watson et al. The broad footprint of climate change from genes to biomes to people. Science, November 2016 DOI: 10.1126/science.aaf7671