🔗 Share this article

The direst possible consequences of the climate crisis for the UK have been detailed by scientists, encompassing a searing 4C increase in mean temperatures to a two-metre rise in ocean levels. An alternative projection foresees a drop of 6C in temperatures following the failure of key Atlantic Ocean currents, which would severely impact farming and energy needs.

Credible Events, Not Predictions

These consequences, a number of which are linked to climate tipping points, are seen as improbable but credible. The team stated that these models plugged a hole in forecasting that had left the UK ill-prepared for worst-case results.

"The severe weather events we have detailed aren’t predictions, but they are credible," stated the lead researcher who oversaw the research. "The UK has been planning in the absence of the frameworks to assess catastrophic outcomes. We've now given policymakers what they need to prepare for climate outcomes they pray never occur, but can’t afford to ignore."

A Spectrum of Harsh Climate Possibilities

A further series of worst-case scenarios maps the projected severity of severe conditions between now and the end of the century. These indicate that temperatures could soar in particular seasons by up to 6C higher than the norm, while precipitation could be triple standard measurements.

The likelihood of the extreme scenarios occurring remains uncertain due to uncertainty about what action will be taken to combat global warming and how the planet's climate will react. This analysis was compared to national security risk assessments or resilience checks for economic stability.

Critical Scenario Elements

• Severe Heating: Global temperatures soaring past 4C by 2100 could occur if emissions cuts fails or if strong feedback loops including the Amazon basin dying unleash its vast reserves of carbon. This would result in severe and lengthy heat domes and droughts affecting the UK in summer.
• Ocean Circulation Failure: A critical sea current, the AMOC, is losing strength and showing signs of collapse due to climate change. A complete failure beginning in 2030 would lead to a drastic cooling in the UK. "Farming would struggle enormously and water resources would be drastically changed," noted Arnell.
• Accelerated Coastal Flooding: A surge of 2.0-2.2 metres around the UK by 2100 could take place if ice sheets in the Arctic and Antarctic collapse rapidly, flooding seaside communities. Unlike the other scenarios, this possibility is already known by infrastructure experts.
• Aerosol Effect: Global averages could also be pushed higher by about 0.75C if industrial aerosols is drastically reduced. This unexpected result occurs because tiny specks from industrial activity block sunlight from reaching the ground.

Preparing for the Extreme

The worst-case scenarios could be utilized in planning the construction of critical national infrastructure, including new towns, energy plants and flood defences. Awareness of these environmental threats could also hasten the transition to cut carbon pollution.

The study developed the extreme models using a mix of past data and records, digital projections and scientific theory. These outcomes omit broader worldwide issues including the global food shortages and geopolitical instability.

This work was requested as part of a government’s adaptation planning initiative. Earlier reports have warned that insufficient focus was being allocated to high-consequence, low-probability risks.

Official experts has recommended that the UK must "become resilient to moderate heating" and examine the threats for severe warming. Past policy documents have been criticised as being "inadequate" by certain experts.

A national response said: "Climate change is at the heart of this government’s agenda, both preparing for impacts and becoming a renewable energy leader. It is vital that the UK is resilient for the impacts."