Sea levels are rising much faster than a century ago, the Met Office’s annual look at Britain’s climate and weather reveals.
The State of the Climate report also says that higher temperatures are the new normal for the UK.
Conservationists warn that spring is coming earlier and that plant and animal life is not developing fast enough to adapt to climate change.
The report again highlights the ways in which climate change is affecting the UK.
Britain is warming slightly faster than the average global temperature rise, it also explained.
The Met Office assessed climate and weather events for 2021, including extreme events such as Storm Arwen which caused devastating flooding.
Sea levels have risen by around 16.5cm (6.5in) since 1900, but the Met Office says the rise is accelerating. They are now increasing by 3-5.2 mm a year, which is more than double the increase at the beginning of the last century.
This exposes several parts of the coast to strong storm surges and winds, and damages the environment and homes. Around 500,000 homes are at risk of flooding, say researchers.
Extreme sea levels during storm Arwen last November were only avoided because it hit during a lower than normal tide, explains Dr Svetlana Jevrejeva from the National Oceanographic Centre.
While coastlines are always changing, climate change and sea level rise are exaggerating those changes, she told BBC News.
“The scale, the speed and the impact will change, and it will change dramatically very soon,” she explains.
The report also says that while the UK climate in 2021 was “unremarkable” by modern standards, it would have been exceptional 30 years ago. That’s because climate change is altering the planet, making warmer temperatures the norm.
Our planet has warmed by 1.1 degrees since the industrial revolution around 200 years ago. The Intergovernmental Panel on Climate Change says this is caused by greenhouse gases from human activities. Over the next 20 years, the global temperature is expected to reach or exceed 1.5 degrees of warming.
Had last year’s temperatures occurred in 1992, it would have been one of Britain’s hottest years on record, it is highlighted.
“While 1 C of warming may not sound like much, it has led to maximum temperatures like the 32.2 C we saw in 2021 becoming the routine rather than the exception. This is particularly stark when you consider the record-breaking heat Britain experienced last week, says Mike Kendon, from the Met Office National Climate Information Centre.
The changing climate is also bringing spring earlier, affecting plants and animals as well as farmers.
Species that come into leaf early in the year were even earlier last year, but unusually cold temperatures in April caused delays for late-blooming species, the Met Office said.
And September and October were warmer than average, which delayed autumn and meant trees lost their leaves later than normal, explained Professor Tim Sparks of the Woodland Trust.