🔗 Share this article

The gravest possible consequences of the climate emergency for the UK have been detailed by experts, including a searing 4C jump in average temperatures to a 2-metre surge in ocean levels. An alternative projection predicts a plunge of 6C in temperature following the collapse of critical Atlantic Ocean currents, which would massively disrupt food production and energy needs.

Plausible Events, Not Forecasts

These impacts, a number of which are associated with climate tipping points, are considered as unlikely but plausible. The researchers stated that these scenarios plugged a hole in planning that had left the UK not ready for extreme outcomes.

"The severe weather events we have outlined aren’t predictions, but they are credible," said the professor who led the analysis. "Britain has been planning without the tools to assess worst-case scenarios. We've now supplied decision-makers what they need to prepare for environmental results they hope never happen, but dare not dismiss."

A Spectrum of Extreme Weather Projections

A further series of dire projections details the possible scale of extreme weather between now and the end of the century. These suggest that temperatures could rocket in some months by up to 6C above historical levels, while precipitation could be 300% of typical amounts.

The chance of the catastrophic events happening cannot be precisely determined due to a lack of certainty about what action will be taken to tackle global heating and how the Earth's systems will respond. This approach was compared to defence planning or scenario planning for economic stability.

Major Possibility Elements

• 4C Temperature Rise: Planetary heating exceeding 4C by 2100 could occur if climate action collapses or if vicious cycles like the tropical forests dying unleash its enormous store of carbon. This would cause intense and enduring heat domes and droughts affecting the UK in summer.
• AMOC Shutdown: A major ocean current, the AMOC, is weakening and becoming unstable due to ocean warming. A collapse starting around 2030 would lead to a 6C cooling in the UK. "Crop production would struggle enormously and water supplies would be drastically changed," noted the professor.
• Sudden Ocean Inundation: A increase of 2.0-2.2 metres around the UK by 2100 could take place if polar ice in the Arctic and Antarctic collapse rapidly, submerging coastal cities and towns. Differing from the other scenarios, this risk is already known by coastal engineers.
• Aerosol Effect: Temperatures could also be increased by about 0.75C if airborne particulates is sharply cut. This counterintuitive effect occurs because pollution particles from burning coal block solar radiation from warming the ground.

Preparing for the Extreme

The severe models could be used to inform the building of long-term infrastructure, for example new towns, power generation facilities and flood defences. Knowledge about these future hazards could also speed the push to slash fossil fuel emissions.

The analysis created the severe projections using a mix of real-world events, climate models and climate physics. These outcomes omit potential global problems such as the agricultural collapse and geopolitical instability.

The research was commissioned as part of a official adaptation planning initiative. Previous assessments have warned that not enough attention was being paid to catastrophic yet improbable risks.

Official experts has said that the UK must "adapt to 2C" and examine the dangers for four degrees. Previous adaptation plans have been criticised as being "inadequate" by environmental groups.

An official statement said: "The climate emergency is at the core of the country's focus, both preparing for impacts and establishing itself as a renewable energy leader. It is essential that the UK is ready for the effects."