🔗 Share this article

The direst potential impacts of the climate emergency for the UK have been detailed by scientists, encompassing a searing 4C rise in mean temperatures to a two-metre increase in sea level. Another scenario foresees a decline of 6C in temperatures following the failure of crucial Atlantic Ocean currents, which would massively disrupt food production and energy needs.

Possible Outcomes, Not Forecasts

These effects, a number of which are connected to climate tipping points, are viewed as improbable but possible. The scientists said that these models filled a gap in forecasting that had rendered the UK ill-prepared for extreme outcomes.

"The severe weather events we have outlined are not forecasts, but they are possible," said the professor who led the research. "Britain has been making preparations lacking the methods to plan for catastrophic outcomes. We've now provided planners what they need to get ready for future conditions they pray never occur, but can’t afford to ignore."

A Spectrum of Severe Conditions Projections

Another collection of dire projections maps the projected severity of harsh climate between now and the end of the century. These indicate that temperatures could soar in certain periods by up to 6C above the norm, while precipitation could be triple standard measurements.

The likelihood of the catastrophic events occurring cannot be precisely determined due to a lack of certainty about what steps will be taken to combat climate change and how the Earth's systems will behave. This research was likened to defence planning or resilience checks for financial systems.

Major Scenario Details

• Four-Degree Warming: Worldwide averages soaring past 4C by 2100 could transpire if climate action collapses or if vicious cycles like the Amazon basin dying release its vast reserves of carbon. This would lead to extreme and prolonged heatwaves and droughts affecting the UK in summer.
• AMOC Shutdown: A key circulation system, the Atlantic meridional overturning circulation (Amoc), is weakening and showing signs of collapse due to climate change. A full shutdown commencing by 2030 would lead to a drastic cooling in the UK. "Farming would struggle enormously and freshwater availability would be drastically changed," explained the professor.
• Accelerated Coastal Flooding: A increase of 2.0-2.2 metres around the UK by 2100 could take place if glaciers in the polar regions melt abruptly, submerging seaside communities. Differing from the other scenarios, this risk is already known by planners.
• Pollution Paradox: Temperatures could also be driven up by about 0.75C if pollution from industry is rapidly cleaned up. This unexpected result occurs because aerosol particles from burning coal reflect sunlight from warming the ground.

Planning for the Unthinkable

The severe models could be used to inform the development of critical national infrastructure, including new towns, nuclear power stations and flood defences. Understanding these environmental threats could also speed the drive to slash carbon pollution.

The analysis created the extreme models using a combination of observed and historical experience, climate models and established principles. The scenarios do not take into account international cascading effects including the devastation of food supplies and increased conflict.

This work was commissioned as part of a official adaptation planning initiative. Previous assessments have stated that insufficient focus was being allocated to catastrophic yet improbable risks.

An independent advisory body has recommended that the UK needs to "become resilient to moderate heating" and evaluate the threats for 4C. Past policy documents have been described as being "insufficient" by certain experts.

An official statement commented: "The climate emergency is at the core of this government’s agenda, both adapting for the future and establishing itself as a renewable energy leader. It is essential that the UK is resilient for the effects."