A new study suggests that global warming that’s twice as bad may be in store for humans in the future.
The new projections are rather grim: the polar ice caps could collapse and the Sahara Desert could become green as a result of aggressive changes in various ecosystems.
Global warming may be twice as projected by climate models and sea levels may rise 20 feet even if the world meets the 35.6 degrees Fahrenheit target, an international team of researchers from 17 nations noted in the new research.
The team explored evidence from three warm periods that occurred in the last 3.5 million years when Earth was 32.9 degrees F (0.5 degrees Celsius) to 35.6 degrees F (2 degrees C) hotter than pre-industrial 19th-century temperatures.
In their observations, the team saw that there are “amplifying mechanisms,” not well-represented in climate models, which make long-term warming worse than what is forecasted in climate models.
"This suggests the carbon budget to avoid 2°C of global warming may be far smaller than estimated, leaving very little margin for error to meet the Paris targets,” said Hubertus Fischer, lead author and University of Bern professor.
The researchers derived their conclusion from their analysis of three warm periods, namely the Holocene thermal maximum period some 5,000 to 9,000 years earlier, the last interglacial period 129,000 to 116,000 years ago, and the mid-Pliocene period some 3.3 to 3 million years earlier.
They combined measurements from the likes of ice cores and fossil records, then studied the impact of the climatic changes. The first two periods, for instance, warmed from predictable changes that happened in the planetary orbit.
The periods offered strong proof of how much warmer Earth would become after the climate normalized. Sea-level rise could persist for thousands of years, warned Alan Mix, co-author and Oregon State professor.
Present Climate Models Are Focused On Near Team
These profound changes can hit the planet even potentially with just 34.7 degrees F or 1.5 degrees C, yet climate projects today generally underestimate them as implications of long-term warming, Mix said.
He explained that these models may be relied upon for low-emission scenarios in the decades leading up to 2100, but not really for larger or higher-emission scenarios.
Parts of the world continue to grapple with the ongoing symptoms and effects of climate change. U.S. homeowners, for instance, face a particular threat: sea-level flooding could wipe out more than 300,000 homes in the country.
The findings are discussed in the journal Nature Geoscience.