2015: The year in extreme weather

Meteorological madness from heatwaves to cyclones and wildfires has marked the year, in a taste of global warming impacts

Composite image of tropical cyclones Nineteen, Nathan and Pam, generated at 09:00 UTC on 11 March 2015 (Pic: NASA)

Composite image of tropical cyclones Nineteen, Nathan and Pam, generated at 09:00 UTC on 11 March 2015 (Pic: NASA)

By Alex Pashley

Climate scientists may hesitate to link individual instances of extreme weather to climate change, but they are convinced human activities are increasing the risks. 

2015 is set to be the hottest year since records began, fuelled by carbon emissions and a strong El Nino, says the UN’s weather agency. That’s until 2016 beats it, the UK’s Met Office forecasts.

Temperatures have now risen 1C on pre-industrial levels – halfway to the 2C threshold regarded as a ‘guardrail’ for avoiding the most dangerous consequences.

Here are last year’s weather phenomena NASA linked to man-made climate change. What role did it play this year?

Heatwaves in India and Pakistan killed thousands

Villagers taking shower under a solar-powered water pump at Dharnai village in Bihar, India (Pic: Avik Roy)

Villagers taking shower under a solar-powered water pump at Dharnai village in Bihar, India (Pic: Avik Roy)

Sweltering heat claimed the lives of more than 2,000 people in India and 1,000 in Pakistan in May and June. High humidity and low air pressure produced little breeze, making conditions far less bearable for people and animals. Temperatures peaked in Karachi at 43C, while tarmac across the border melted.

Coral reefs bleached by warm seas

A fire coral in Bermuda, before and after bleaching (Pic: XL Catlin Seaview Survey)

A fire coral in Bermuda, before and after bleaching (Pic: XL Catlin Seaview Survey)

Corals bleached across the world’s oceans in only the third die-off of its scale in history. US agency NOAA expects warm seas to deplete more than 38% of world’s reefs by end of the year. It can take 10-15 years for coral to grow back, with the sensitive ecosystem that supports marine life only regaining its former strength after 20-30 years.

Haze from Indonesia forest fires choked southeast Asia

Thick smoke blankets the islands of Borneo and Sumatra, which has led to air quality and public health warnings in Indonesia and neighbours Malaysia, Singapore and Thailand (credit: NASA Earth Observatory/Adam Voiland)

Thick smoke blankets the islands of Borneo and Sumatra, which has led to air quality and public health warnings in Indonesia and neighbours Malaysia, Singapore and Thailand (credit: NASA Earth Observatory/Adam Voiland)

The worst fires in 18 years caused toxic smog that emitted as much as carbon as the US economy on certain days. The fires were largely deliberate, to clear forest and peatland for agriculture, but dry conditions due to El Nino fanned the flames. They caused respiratory illness, soured relations with affected Malaysia and Singapore and cut short a visit to Washington for the country’s president.

Yemen buffeted by two rare cyclones

On Nov. 9 at 10:05 UTC (5:05 a.m. EST), the VIIRS instrument aboard NASA-NOAA's Suomi NPP satellite captured a visible image of an elongated Tropical Cyclone Megh in the Gulf of Aden, Arabian Sea. Credit: NASA/NOAA, Jeff Schmaltz Read more at: http://phys.org/news/2015-11-nasa-elongated-tropical-cyclone-megh.html#jCp

On Nov. 9 at 10:05 UTC (5:05 a.m. EST), the VIIRS instrument aboard NASA-NOAA’s Suomi NPP satellite captured a visible image of an elongated Tropical Cyclone Megh in the Gulf of Aden, Arabian Sea. Credit: NASA/NOAA, Jeff Schmaltz

Strong tropical cyclones battered Yemen in November, causing flooding unseen for decades. First Cyclone Chapala hit the war-torn country, then Megh the following week. WMO’s Clare Nullis told the BBC back-to-back events were an “absolutely extraordinary event”. Warm waters helped water evaporate to join the brewing hurricance, with little wind offering no resistance, reported TIME.

Ethiopia suffers chronic drought

 © European Union/ECHO/Melaku Asefa

Women wait at a well for water (credit: EU/ECHO/Melaku Asefa)

Ethiopia is experiencing its worst drought in 30 years after two consecutive poor rainy seasons. Humanitarian aid has prevented the parched Amhara and Afar regions from becoming a full-scale disasters. But the UN has warned over 8 million people will be need in of food aid by the start of 2016 if resources aren’t stepped up.

Wildfires roil the western United States

The US army battles wildfires over Yosemite national park in August 2013 (Flickr/ US Army)

The US army battles wildfires over Yosemite national park in August 2013 (Flickr/ US Army)

This year has been the most devastating year on record for wildfires in the US. More than 9 million acres have burned this year, according to official figures, as blazes raged across the western US from Montana to California and Texas. The fire season has extended by two months since the early 1970s, to seven months according to the Union of Concerned Scientists. The number of large fires has jumped from an annual average of 140 from 1980-89 to 250 from 2000-12.

Bad flooding hits India 

The heaviest rainfalls in over a century devastated parts of the southern Indian state of Tamil Nadu. A strong monsoon deluged the city of Chennai – with more than 300 deaths according to official figures and billions of dollars in property damage. The Times of India cited El Nino as a factor, as warmer ocean surface temperatures had led to evaporation and moisture-rich air turning to precipitation in the region.

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