New research: climate may be more sensitive and situation more dire | Dana Nuccitelli

When comparing apples to apples, a new study finds energy budget climate sensitivity estimates consistent with climate models Scientists use a variety of approaches to estimate the Earth’s climate sensitivity – how much the planet will warm as a result of humans increasing greenhouse effect. For decades, the different methods were all in good general agreement that if we double the amount of carbon dioxide in the atmosphere, Earth’s surface temperatures will immediately warm by about 1–3°C (this is known as the ‘transient climate response’). Because it would take decades to centuries for the Earth to reach a new energy balance, climate scientists have estimated an eventual 2–4.5°C warming from doubled atmospheric carbon (this is ‘equilibrium climate sensitivity’).However, a 2013 paper led by Alexander Otto disrupted the agreement between the various different approaches. Using a combination of recent climate measurements and a relatively simple climate model, the ‘energy budget’ approach used in Otto’s study yielded a best estimate for the immediate (transient) warming of 1.3°C and equilibrium warming of 2.0°C; within the agreed range, but less than climate model best estimates of 1.8°C and 3.2°C, respectively. Continue reading...
Source: Guardian Unlimited Science - Category: Science Authors: Tags: Climate change scepticism Environment Greenhouse gas emissions Science Source Type: news