He urged politicians not to abandon European leadership in combating global warming as it causes "enormous changes" to the planet.

Josef Aschbacher, director general of the European Space Agency, made the comments as wildfires burn in Portugal, Tenerife and Canada.

At least 106 people have died after devastating fires in Hawaii in recent days.

Spanish authorities ordered the evacuation of four villages on the Canary island on Wednesday after a fire broke out in a nature park surrounding the Mount Teide volcano.

The fire, which started on Tuesday night, was raging through a forested area in steep ravines in the northeastern part of Tenerife, making firefighters' task more difficult.

It comes after the Canary Islands were hit by a heatwave that left many areas bone dry, increasing the risk of wildfires.

In Canada's Northwest Territories, the authorities have declared a state of emergency due to wildfires that have largely destroyed a remote community and now pose a risk to the territorial capital, Yellowknife.

There have been 265 wildfires in the Northwest Territories this year, much higher than its 10-year annual average of 185.

Wildfires have engulfed parts of nearly all 13 Canadian provinces and territories this year, forcing home evacuations, disrupting energy production, and drawing in federal as well as international firefighting resources.

The World Meteorological Organisation said July had the highest global average temperature for any month on record.

"This is really alarming," Mr Aschbacher, a leading expert on environmental observation, said.

"It just confirms that climate change is the biggest threat to our planet, to humankind, and will remain so for the next decades and we do need to do everything we can to mitigate the effects."

Read more:
Countries worst affected by extreme water stress
Factors behind Hawaii's devastating wildfires
Scientists predict how often heatwaves will now occur

Scientists say climate change is making heatwaves more frequent, intense and likely to happen across seasons, not just in what were regarded as the summer months.

But pressure is growing on some governments over the cost of net-zero commitments on emissions, and analysts say looming elections in Europe could put future measures at risk.

In Britain, Prime Minister Rishi Sunak has warned of climate policies that "unnecessarily give people more hassle and more costs".

Mr Ashbacher said long-term costs were likely to be far higher unless governments respond to "crystal clear" evidence, including satellite measurements, of the recent heat emergency in southern Europe.