LONDON, United Kingdom -- Sea levels are increasing around Britain at a far faster rate than a century ago, while the country is warming slightly more than the global average, leading meteorologists said on Thursday.

Their latest annual State of the UK Climate study -- compiled by the country's meteorological authority, the Met Office -- reiterated that recent decades have been "warmer, wetter and sunnier" than those in the 20th century.

The report covering 2021 comes hot on the heels of a heatwave last week that saw temperatures top 40 degrees Celsius (104 degrees Fahrenheit) in England for the first time, setting a record at 40.3C.

The Environment Agency has urged people to use water "wisely" to protect supplies and the environment, after the Met Office said the first half of this year had been among the driest on record.

"The report is very clear that we are seeing a change in our climate, whether that's temperature, precipitation, sea level rise," said Liz Bentley, of the Royal Meteorological Society, which publishes the study in its International Journal of Climatology.

The Met Office said in a summary that its latest findings reaffirmed "climate change is not just a problem for the future and that it is already influencing the conditions we experience here at home".

Meteorologists noted in the report that sea levels over the last three decades had increased in some places at more than double the rate recorded at the start of the 1900s.

They have risen by around 16.5 centimetres (6.5 inches) since 1990 -- approximately three to 5.2 mms each year, compared to 1.5 mms annually in the early part of last century.

This is exposing more areas of coastal land to larger and more frequent storm surges and "wind-driven wave impacts", the Met Office said.

- Dramatic change -
Svetlana Jevrejeva of the National Oceanographic Centre said there was evidence that the rises were due to the increased rate of ice loss from the Greenland and Antarctic ice sheets.

Glacier melting around the world and the warming of the ocean were also responsible, she noted, adding that the effect on Britain's coastline would only grow.

"The scale, rate and impact will change and it will change dramatically quite soon," Jevrejeva told the BBC.

The annual study also found that Britain has warmed at a broadly consistent but "slightly higher" rate than global mean temperature rises.

The Met Office's Mike Kendon, the study's lead author, said record temperatures, such as last week's unprecedented heatwave, were "becoming routine rather than the exception".

"It is telling that whereas we consider 2021 as near-average for temperature in the context of the current climate, had this occurred just over three decades ago it would have been one of the UK's warmest years on record," he added.

The UK hosted the UN's COP26 summit last November, when scores of countries agreed collective measures to try to prevent catastrophic climate change.

But fears are growing that many countries could stall on delivering pledges -- including on ending financing fossil fuel projects abroad -- as they struggle to replace Russian energy imports.

In Britain, Foreign Secretary Liz Truss -- the favourite in a leadership battle to replace outgoing Prime Minister Boris Johnson -- has vowed to axe energy bill levies earmarked for the renewable sector.

She has insisted that is needed to help people through a worsening cost-of-living crisis.

US climate envoy John Kerry last week warned Britain's next leader that the commitment to net-zero greenhouse gas emissions by 2050 cannot be compromised.

"We do not have the luxury of jiggering with the 2050 right now," he told BBC radio.