Heavy rain and flooding fit with climate change predictions
The record-breaking rainfall and devastating flooding which have hit parts of the UK fit with expert predictions for how the country will be affected by climate change.
While scientists will not point to a single event and say it has been caused by global warming, they are clear that human influence on the climate is loading the dice in favour of these extreme events.
Greenhouse gas emissions from power generation, industry, transport, deforestation and agriculture are pushing up global temperatures.
Warmer temperatures mean the atmosphere can hold more water, with humidity increasing around 5% for every 1C rise, which in turn prompts more intense rainfall and storms.
Heavy rainfall can cause flash flooding, where rain falls too quickly to soak into the ground - especially if it is already saturated from previous storms, or baked hard by previously dry conditions as in the 2007 summer floods - and causes floods on road and land surfaces.
It can also cause river flooding, when rivers are overwhelmed with the amount of water that is flowing into them.
Increased storminess can batter coasts and cause storm surges which combine with rising sea levels - also caused by climate change - to lead to coastal flooding where defences fail.
One of the predicted consequences for the UK of climate change is an increase in very wet winters, such as the one seen in 2013/2014 - the wettest winter on record for England and Wales - extreme weather and flooding.
In the wake of the 2013/2014 winter, which saw widespread flooding and coastal damage, researchers from Oxford University found climate change was already making this kind of intensely wet winter 25% more likely, meaning that what would be a one-in-100-year event has became a one-in-80-year event.
Periods of intense rainfall could increase in frequency by a factor of five this century as global temperatures rise, the Government's advisory Committee on Climate Change has warned.
Because of the greater risk of extremely wet weather, defences that were designed to stand against a one-in-100-year event will provide a lower level of protection and be overwhelmed more frequently,
Despite spending on defences, the number of homes and businesses at risk will increase in future decades, the committee says.
But how much worse extreme weather and flooding becomes will depend on the efforts the world takes to curb rising temperatures.
If temperature rises are limited to 2C - seen as the threshold beyond which "dangerous" climate change is expected - the UK's flood risk should be manageable, but if global temperatures soar by 4C, flood damage would double even if the Government continues to invest in defences, the CCC warns.
The flooding of the past few days throws into sharp relief the need for countries now meeting at crucial United Nations talks in Paris to secure a new international deal that will avoid dangerous climate change and its impacts.
