🔗 Share this article

The gravest projected effects of the climate emergency for the UK have been mapped by scientists, ranging from a searing 4C jump in temperatures to a 2-metre rise in sea level. Another scenario predicts a plunge of 6C in temperature following the failure of crucial Atlantic Ocean currents, which would severely impact farming and power requirements.

Plausible Extremes, Not Forecasts

These consequences, certain ones are connected to irreversible climate shifts, are considered as unlikely but credible. The scientists stated that these models addressed a shortfall in risk assessment that had left the UK ill-prepared for extreme outcomes.

"The climate extremes we have detailed are not forecasts, but they are plausible," said the professor who oversaw the research. "The UK has been formulating policy in the absence of the tools to plan for extreme possibilities. We've now provided policymakers what they need to plan for environmental results they wish to avoid, but can’t afford to ignore."

A Range of Harsh Climate Scenarios

A further series of worst-case scenarios details the possible scale of harsh climate between now and the close of the 2100s. These suggest that thermometer readings could soar in particular seasons by up to 6C above the norm, while rainfall could be three times normal levels.

The chance of the catastrophic events occurring remains uncertain due to unknown factors about what steps will be enacted to address global heating and how the planet's climate will respond. This research was compared to national security risk assessments or resilience checks for economic stability.

Key Scenario Details

• Severe Heating: Planetary heating rising well above 4C by 2100 could occur if international cooperation fails or if vicious cycles like the Amazon basin perishing emit its huge repository of carbon. This would cause extreme and prolonged heatwaves and dry spells plaguing the UK in summer.
• AMOC Shutdown: A critical sea current, the Atlantic meridional overturning circulation (Amoc), is slowing down and becoming unstable due to ocean warming. A complete failure commencing by 2030 would lead to a six-degree temperature drop in the UK. "Agriculture would face immense difficulties and water supplies would be drastically changed," explained Arnell.
• Accelerated Coastal Flooding: A increase of 2.0-2.2 metres around the UK by 2100 could occur if glaciers in Greenland and Antarctica collapse rapidly, inundating low-lying areas. Differing from the other scenarios, this threat is already known by coastal engineers.
• Clean Air Warming: Global averages could also be pushed higher by about 0.75C if pollution from industry is sharply cut. This paradoxical outcome occurs because aerosol particles from burning coal scatter sunlight from warming the ground.

Preparing for the Worst

The severe models could be used to inform the building of long-term infrastructure, for example new towns, power generation facilities and water management networks. Knowledge about these climate risks could also accelerate the transition to slash carbon pollution.

The analysis created the worst-case scenarios using a blend of observed and historical experience, digital projections and climate physics. The possibilities do not take into account international cascading effects including the devastation of food supplies and geopolitical instability.

The research was commissioned as part of a government’s adaptation planning initiative. Earlier reports have stated that too little consideration was being given to high-consequence, low-probability risks.

An independent advisory body has said that the UK needs to "become resilient to moderate heating" and assess the risks for four degrees. Past policy documents have been described as being "insufficient" by some observers.

An official statement commented: "Climate change is at the center of the country's focus, both building resilience and becoming a clean energy superpower. It is crucial that the UK is ready for the impacts."