Posted: 10 Nov 2016 12:33 PM PST
It is well-established in the scientific community that increases in atmospheric CO2 levels result in global warming, but the magnitude of the effect may vary depending on average global temperature. A new study, published this week in Science Advances …concludes that warm climates are more sensitive to changes in CO2 levels than cold climates….
“Our results imply that Earth’s sensitivity to variations in atmospheric CO2 increases as the climate warms,” explained Friedrich. “Currently, our planet is in a warm phase — an interglacial period — and the associated increased climate sensitivity needs to be taken into account for future projections of warming induced by human activities.”
Using these estimates based on Earth’s paleoclimate sensitivity, the authors computed the warming over the next 85 years that could result from a human-induced, business-as-usual greenhouse gas emission scenario. The researchers project that by the year 2100, global temperatures will rise 5.9°C (~10.5°F) above pre-industrial values. This magnitude of warming overlaps with the upper range of estimates presented by the Intergovernmental Panel on Climate Change (IPCC)….
The results of the study demonstrate that unabated human-induced greenhouse gas emissions are likely to push Earth’s climate out of the envelope of temperature conditions that have prevailed for the last 784,000 years. “The only way out is to reduce greenhouse gas emissions as soon as possible,” concluded Friedrich.