The gravest possible consequences of the climate emergency for the UK have been outlined by scientists, encompassing a blistering 4C jump in temperatures to a two-metre surge in ocean levels. A separate possibility envisions a drop of 6C in temperatures following the collapse of critical Atlantic Ocean currents, which would profoundly upset farming and energy needs.
Plausible Extremes, Not Forecasts
These effects, a number of which are connected to critical climate thresholds, are considered as unlikely but plausible. The scientists explained that these projections filled a gap in risk assessment that had rendered the UK unprepared for worst-case results.
"The climate extremes we have outlined are not forecasts, but they are possible," stated the lead researcher who led the research. "Britain has been formulating policy in the absence of the frameworks to plan for catastrophic outcomes. We've now provided planners what they need to plan for future conditions they wish to avoid, but must not overlook."
A Suite of Extreme Weather Possibilities
Another collection of severe models maps the projected severity of extreme weather between now and the year 2100. These suggest that thermometer readings could soar in particular seasons by up to 6C above the norm, while rainfall could be 300% of typical amounts.
The likelihood of the extreme scenarios happening cannot be precisely determined due to uncertainty about what steps will be taken to combat climate change and how the climate system will behave. This approach was described as similar to national security risk assessments or resilience checks for economic stability.
Key Outcome Details
- Severe Heating: Worldwide averages soaring past 4C by 2100 could occur if climate action fails or if vicious cycles such as the Amazon basin becoming a net carbon source unleash its vast reserves of carbon. This would cause intense and enduring heatwaves and dry spells hitting the UK in summer.
- Atlantic Current Collapse: A major ocean current, the AMOC, is losing strength and losing stability due to ocean warming. A complete failure commencing by 2030 would lead to a drastic cooling in the UK. "Farming would face immense difficulties and freshwater availability would be drastically changed," explained Arnell.
- Sudden Ocean Inundation: A increase 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. In contrast to the other scenarios, this risk is already recognized by infrastructure experts.
- Clean Air Warming: Temperatures could also be driven up by about 0.75C if pollution from industry is sharply cut. This unexpected result occurs because aerosol particles from burning coal block sunlight from warming the ground.
Planning for the Worst
The worst-case scenarios could be utilized in planning the building of critical national infrastructure, for example housing developments, power generation facilities and water management networks. Knowledge about these environmental threats could also accelerate the transition to cut fossil fuel emissions.
The research created the worst-case scenarios using a mix of observed and historical experience, computer simulations and established principles. These outcomes omit international cascading effects including the global food shortages and resource wars.
This work was requested as part of a national adaptation planning initiative. Earlier reports have stated that not enough attention was being paid to catastrophic yet improbable risks.
An independent advisory body has said that the UK must "become resilient to moderate heating" and evaluate the threats for four degrees. Previous adaptation plans have been described as being "inadequate" by environmental groups.
An official statement commented: "Climate change is at the heart of this government’s agenda, both building resilience and becoming a clean energy superpower. It is vital that the UK is prepared for the effects."
