Flash-flood-hit London is going to suffer more torrential downpours and heatwaves under scenarios outlined in an authoritative new report on Monday.
It also raised fears that the capital’s tower block building bonanza will worsen heatwaves in the city fuelled by global warming.
The city has seen a series of flash floods in recent weeks which have disrupted Tube stations, hospitals, major roads, leaving some businesses and homes swamped with water.
The report by the Intergovernmental Panel on climate change laid bare how these extreme weather events are set to increase in coming years with global temperatures set to rise by more than 1.5C, compared to the pre-industrial era, by 2041-2060.
In a section on Europe, it stated: “Extreme precipitation and pluvial flooding are projected to increase at global warming levels exceeding 1.5C in all regions except the Mediterranean.”
It also warned of more rainfall during winter in northern Europe, which includes the UK, and that temperatures will rise in all European areas at a rate exceeding global average changes.
In addition, it highlighted threats to cities including London due to the “urban heat island effect”.
With more and more tall buildings being built in inner London boroughs, as well as suburbs, it emphasised three main factors which “amplify the warming of urban areas”.
- Urban geometry. Tall buildings close to each other absorb and store heat and also reduce natural ventilation.
- Human activities, due to heat released from domestic and industrial heating or cooling systems, running engines, and other sources
- The materials that make up cities. These materials are very good at absorbing and retaining heat and then re-emitting that heat at night.
- Cities with limited parks and other vegetation will be more at risk.
The authoritative study, agreed by 195 countries, gave the starkest warning yet of the threat from climate change, with “best estimate” projections that global temperatures will have risen by at least 1.5 degrees C, from pre-industrial levels, by 2021-2040, earlier than a prediction just three years ago of this being reached between 2030 and 2052.
It will pile pressure on governments to stop kicking the can down the road and finally agree decisive action to stop catastrophic warming of the earth at the COP26 climate change summit in November in Glasgow.
The study stressed that:
- Global warming of 1.5°C and 2°C will be exceeded during the 21st Century unless deep reductions in CO2 and other greenhouse gas emissions occur in the coming decades.
- Global surface temperature will continue to increase until at least the mid-century under all emissions scenarios considered.
- Many of the changes observed in the climate are unprecedented in thousands, if not hundreds of thousands of years.
- Some of the changes already set in motion – such as continued sea level rise and melting ice sheets – are irreversible over hundreds to thousands of years.
- Unless there are immediate, rapid and large-scale reductions in greenhouse gas emissions, limiting warming to close to 1.5°C or even 2°C will be beyond reach.
- Emissions of greenhouse gases from human activities are responsible for approximately 1.1°C of warming since 1850-1900, and averaged over the next 20 years, global temperature is expected to reach or exceed 1.5°C of warming. A 1.5C rise above pre-industrial levels is a limit that countries have pledged to try to avoid breaching because of the dangerous consequences for humanity.
- For 1.5°C of global warming, there will be increasing heat waves, longer warm seasons and shorter cold seasons. At 2°C of global warming, heat extremes would more often reach critical tolerance thresholds for agriculture and health.
- Climate change is intensifying the water cycle. This brings more intense rainfall and associated flooding, as well as more intense drought in many regions.
- Extreme sea level events that previously occurred once in 100 years could happen every year by the end of this century.
- Further warming will amplify permafrost thawing, and the loss of seasonal snow cover, melting of glaciers and ice sheets, and loss of summer Arctic sea ice.
IPCC Working Group I Co-Chair Panmao Zhai said: “Climate change is already affecting every region on Earth, in multiple ways. “The changes we experience will increase with additional warming.”
Article courtesy of the Evening Standard