An increase of 1.5 °C (2.7 °F) above pre-industrial average temperatures is seen as a dangerous threshold for the climate of our planet. The official Intergovernmental Panel on Climate Change (IPCC) estimated that it could happen by 2052. A new study has put forward a stricter range; the threshold will be crossed between 2027 and 2042.
As reported in Climate Dynamics, researchers have developed a Scaling Climate Response Function (SCRF) to extrapolate changes to temperatures up to the year 2100. The new method differs from the General Circulation Models (GCMs) used by the IPCC, which try to simulate the complexity of the climate of the entire planet.
"Our new approach to projecting the Earth's temperature is based on historical climate data, rather than the theoretical relationships that are imperfectly captured by the GCMs. Our approach allows climate sensitivity and its uncertainty to be estimated from direct observations with few assumptions," co-author Raphaël Hébert, from the Alfred-Wegener-Institut in Potsdam, said in a statement.
The method cuts prediction uncertainties in half, and at the same time confirms that the “very likely warming ranges” for the next 80 years were consistent with those expected by the GCMs. This is extremely positive, given how differently these estimations were obtained. The increase in warming with the SCRF was slightly gentler – 10 to 15 percent lower than the average for the GMCs – but well within the uncertainties.
The work adds to the cacophony of alarm bells on the state of the climate, and the absolute urgency to have strong measures to mitigate global warming. The climate can’t be fixed at a press of a button, it requires long-term solutions, and those take time.
"Now that governments have finally decided to act on climate change, we must avoid situations where leaders can claim that even the weakest policies can avert dangerous consequences," added co-author Shaun Lovejoy, a physics professor at McGill University. "With our new climate model and its next generation improvements, there's less wiggle room."
The average global temperature in 2019 was 1.1 °C (2 °F) above the pre-industrial level, and throughout 2020 monitoring agencies have registered months among the hottest on record. The effects of the climate crisis are not a distant worry. They are already here.
We had dramatic devastation to marine ecosystems due to increasing temperatures and ocean acidification, the extent of ice in both the Arctic and Antarctica is reaching historically low levels, and the headlines are filled with natural disasters including floods, drought, heatwaves, storms, and wildfires.