🔗 Share this article

The most severe potential impacts of the global heating for the UK have been mapped by researchers, including a scorching 4C increase in mean temperatures to a 6.5-foot rise in sea levels. An alternative projection foresees a drop of 6C in temperatures following the collapse of crucial Atlantic Ocean currents, which would severely impact agriculture and energy needs.

Plausible Outcomes, Not Guarantees

These consequences, certain ones are linked to climate tipping points, are viewed as low probability but plausible. The team explained that these models plugged a hole in planning that had left the UK not ready for worst-case results.

"The severe weather events we have outlined are not forecasts, but they are possible," stated the lead researcher who led the research. "Britain has been planning without the tools to assess catastrophic outcomes. We've now provided policymakers what they need to get ready for future conditions they hope never happen, but dare not dismiss."

A Suite of Severe Conditions Possibilities

A further series of worst-case scenarios maps the possible scale of harsh climate between now and the year 2100. These indicate that temperatures could rocket in particular seasons by up to 6C higher than historical levels, while precipitation could be 300% of normal levels.

The likelihood of the extreme scenarios happening remains uncertain due to a lack of certainty about what measures will be enacted to tackle global heating and how the Earth's systems will behave. This approach was likened to national security risk assessments or stress tests for economic stability.

Major Outcome Details

• Severe Heating: Worldwide averages soaring past 4C by 2100 could occur if international cooperation collapses or if powerful amplifying effects like the Amazon rainforest dying emit its huge repository of carbon. This would result in extreme and prolonged heatwaves and droughts affecting the UK in summer.
• AMOC Shutdown: A key circulation system, the AMOC, is losing strength and showing signs of collapse due to climate change. A complete failure starting around 2030 would lead to a 6C cooling in the UK. "Crop production would face immense difficulties and water resources would be fundamentally reshaped," said the lead researcher.
• Rapid Sea Level Rise: A rise of 2.0-2.2 metres around the UK by 2100 could happen if ice sheets in the Arctic and Antarctic collapse rapidly, submerging low-lying areas. Unlike the other scenarios, this threat is already recognized by infrastructure experts.
• Aerosol Effect: Temperatures could also be pushed higher by about 0.75C if pollution from industry is rapidly cleaned up. This unexpected result occurs because aerosol particles from fossil fuel combustion scatter solar radiation from reaching the ground.

Planning for the Unthinkable

The worst-case scenarios could be used to inform the construction of critical national infrastructure, for example housing developments, nuclear power stations and flood defences. Knowledge about these future hazards could also accelerate the transition to slash greenhouse gas emissions.

The analysis developed the severe projections using a mix of real-world events, climate models and established principles. The possibilities exclude international cascading effects like the global food shortages and increased conflict.

The research was requested as part of a national climate resilience programme. Independent analyses have warned that insufficient focus was being paid to low‐likelihood but high‐impact risks.

The government's climate advisors has stated that the UK must "prepare for two degrees of warming" and evaluate the dangers for severe warming. Past policy documents have been described as being "very weak" by some observers.

An official statement commented: "The climate emergency is at the core of our national priorities, both preparing for impacts and transitioning to a renewable energy leader. It is essential that the UK is prepared for the consequences."