How much could temperatures rise? As the image shows, a rise of more than 10°C (18°F) could take place, resulting in mass extinction of many species, including humans.
How fast could such a temperature rise eventuate? As above image also shows, such a rise could take place within a few years. The polynomial trend is based on NASA January 2012-February 2017 anomalies from 1951-1980, adjusted by +0.59°C to cater for the rise from 1750 to 1951-1980. The trend points at a 3°C rise in the course of 2018, which would be devastating. Moreover, the rise doesn't stop there and the trend points at a 10°C rise as early as the year 2021.
Is this polynomial trend the most appropriate one? This has been discussed for years, e.g. at the Controversy Page, and more recently at Which Trend Is best?
The bottom of the image shows the warming elements that add up to the 10°C (18°F) temperature rise. Figures for five elements may be overestimated (as indicated by the ⇦ symbol) or underestimated (⇨ symbol), while figures in two elements could be either under- or overestimated depending on developments in other elements. Interaction between warming elements is included, i.e. where applicable, figures on the image include interaction based on initial figures and subsequently apportioned over the relevant elements.
Warming elements are discussed in more detail at the Extinction Page, while specific elements are also discussed in posts, e.g. methane hydrates are discussed at Methane Erupting From Arctic Ocean, decline of the snow and ice cover and associated feedbacks is discussed at Arctic Ocean Feedbacks and less take-up by oceans of CO₂ and heat from the atmosphere is discussed at 10°C or 18°F warmer by 2021?
The situation is dire and calls for comprehensive and effective action as described in the Climate Plan.
• Climate Plan
• Which Trend Is best?
• 10°C or 18°F warmer by 2021?
• Arctic Ocean Feedbacks
• Methane Erupting From Arctic Ocean
• Warning of mass extinction of species, including humans, within one decade