Some extreme weather events last year, heat waves in Europe, Asia and Australia, floods or fires in Alaska, Florida, have been exacerbated by global warming, according to an international study published Thursday.

However, it has not detected a link between global warming and other unusual events, such as a delay of the rainy season in Nigeria or heavy rainfall responsible for flooding in India in December.

The authors did not further observed signature of climate change in the unusual severity of the winter in Canada and the northeastern United States in 2015, which was also the warmest year on world since the early temperature readings in 1880.

These works are based on 25 studies conducted by 116 scientists from 18 countries on five continents and two oceans.

This is the fifth annual report on the study of the influence of global warming attributed by most scientists to emissions of greenhouse gases produced by human activities, and extreme weather events.

"After five years of publication of these studies, we see growing evidence that climate change makes extreme heatwaves in many parts of the globe," said Stephanie Herring, a scientist from the US Agency of the oceans and the atmospheric Administration (NOAA), a lead author of the report published in a special edition of the Bulletin of the American Meteorological Society.

"As we improve our ability to distinguish between the influence of climate change and the natural variability, the extent of the regional impacts of this global phenomenon is becoming increasingly clear," she says.

The strongest evidence of human influence on climate have been observed in weather phenomena associated with rising temperatures, the report said.

Sunny winters in the UK

"Experiments with modeling indicate that climate change induced by humans was a major factor in creating the conditions" of these heat waves.

In addition to a greater intensity of heat waves in 2015, researchers also point out that warming has led to a reduction of snow cover in North America and an area of ​​a record low Arctic sea ice in March, at the of winter.

The researchers also concluded that global warming may have played a role in flooding in September 2015 in Miami, due to a particularly high tide.

This phenomenon of tides causing flooding, even though the weather is beautiful these days, has increased 500% since 1994, according to the report.

The scientists also determined that climate change may have contributed to record the intensity of typhoons in the northwest Pacific last year, and the winter sunshine record in the UK over the last two years.

Warming is also involved in the spread and the unprecedented duration of forest fires in Alaska, where nearly 2.1 million hectares burned in 2015, the second largest area since observations began in 1940.

According to these researchers, "climate change induced by humans could have increased the risk of these fires during the season from 34 to 60% fire".

The monthly temperature records show that 2016 is poised to beat a new annual record heat on the globe, which will be the third consecutive.

Climatologists believe the frequency and intensity of extreme weather events are likely to worsen with continued global warming, accelerating the melting of glaciers and Arctic sea ice. This will inevitably raise the level of the oceans.