The most severe possible consequences of the climate emergency for the UK have been detailed by researchers, ranging from a scorching 4C jump in average temperatures to a two-metre increase in ocean levels. A separate possibility predicts a decline of 6C in temperatures following the shutdown of critical Atlantic Ocean currents, which would severely impact food production and power requirements.
Possible Events, Not Forecasts
These consequences, a number of which are linked to irreversible climate shifts, are seen as improbable but possible. The scientists said that these scenarios addressed a shortfall in risk assessment that had rendered the UK ill-prepared for catastrophic possibilities.
"The climate extremes we have outlined should not be seen as certainties, but they are plausible," said Nigel Arnell who oversaw the research. "The UK has been formulating policy lacking the methods to plan for worst-case scenarios. We've now supplied policymakers what they need to prepare for future conditions they pray never occur, but can’t afford to ignore."
A Suite of Extreme Weather Projections
A second set of worst-case scenarios details the possible scale of harsh climate between now and the close of the 2100s. These show that thermometer readings could rocket in some months by up to 6C above average, while rainfall could be triple standard measurements.
The probability of the extreme scenarios coming to pass could not be calculated due to unknown factors about what action will be implemented to tackle global warming and how the climate system will respond. This approach was described as similar to defence planning or resilience checks for financial systems.
Major Possibility Highlights
- Severe Heating: Planetary heating soaring past 4C by 2100 could happen if climate action fails or if strong feedback loops such as the tropical forests perishing emit its huge repository of carbon. This would cause severe and lengthy heatwaves and water shortages hitting the UK in summer.
- Atlantic Current Collapse: A key circulation system, the AMOC, is weakening and becoming unstable due to global heating. A full shutdown starting around 2030 would lead to a drastic cooling in the UK. "Farming would be severely challenged and water resources would be drastically changed," explained the lead researcher.
- Accelerated Coastal Flooding: A surge of 2.0-2.2 metres around the UK by 2100 could take place if polar ice in the polar regions disintegrate quickly, inundating coastal cities and towns. In contrast to the other scenarios, this possibility is already known by infrastructure experts.
- Pollution Paradox: Global averages could also be driven up by about 0.75C if airborne particulates is rapidly cleaned up. This paradoxical outcome occurs because tiny specks from industrial activity reflect sunlight from warming the ground.
Preparing for the Worst
These dire projections could be utilized in planning the building of major projects, including housing developments, energy plants and urban drainage systems. Understanding these future hazards could also accelerate the transition to cut greenhouse gas emissions.
The research formulated the worst-case scenarios using a blend of past data and records, computer simulations and climate physics. The scenarios omit broader worldwide issues like the agricultural collapse and geopolitical instability.
This work was commissioned as part of a official climate resilience programme. Independent analyses have cautioned that too little consideration was being paid to low‐likelihood but high‐impact risks.
An independent advisory body has recommended that the UK must "adapt to 2C" and assess the dangers for severe warming. Earlier government strategies have been described as being "inadequate" by environmental groups.
A government spokesperson commented: "Climate change is at the heart of the country's focus, both preparing for impacts and transitioning to a clean energy superpower. It is crucial that the UK is resilient for the consequences."
