The effects of global warming on temperature, precipitation levels, and soil moisture are turning many of our forests into kindling during wildfire season.
As the climate warms, moisture and precipitation levels are changing, with wet areas becoming wetter and dry areas becoming drier.
Higher spring and summer temperatures and earlier spring snowmelt typically cause soils to be drier for longer, increasing the likelihood of drought and a longer wildfire season. These hot, dry conditions also increase the likelihood that wildfires will be more intense and long-burning once they are started by lightning strikes or human error.
The costs of wildfires, in terms of risks to human life and health, property damage, and money, are devastating, and they are only likely to increase unless we better address the risks of wildfires and reduce our activities that lead to further climate change.
Nor is the nation’s fiery fate particularly unusual at present. Across much of the northern hemisphere, intense and prolonged heatwaves have triggered disruption and devastation as North America, the Arctic, northern Europe and Africa have sweltered in record-breaking temperatures. In Africa, a weather station at Ouargla, Algeria, in the Sahara desert, recorded a temperature of 51.3C, the highest reliable temperature ever recorded in Africa. In Japan, where temperatures have reached more than 40C, people were last week urged to take precautions after the death toll reached 30 with thousands more having sought hospital treatment for heat-related conditions. And in California increased use of air conditioning units, switched on to counter the scorching conditions there, has led to power shortages.
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But perhaps the strangest impact of the intense heat has been felt in Canada. It too has been gripped by ferocious heat, with Toronto recording temperatures that have exceeded 30C on 18 days so far this year. This figure compares with only nine such days all last summer.
Dozens have died in the withering heat – with startling and grim consequences. Montreal’s morgue has been swamped with the bodies of those who have died because of the heat, and many corpses have had to be stored elsewhere in the city. Montreal coroner Jean Brochu said it was first time the city’s morgue had been overwhelmed this way.
Britain’s scorching weather – which has melted the roof of Glasgow’s Science Centre and parched the lawns of the nation’s historic homes – may have made regular UK headlines. However, it has been relatively mild in impact compared to those experienced in many other parts of the world.
Far from being a parochial problem, the current heatwave is clearly an issue that affects vast stretches of our planet: a global concern not a local one.
But why is so much of our world currently being afflicted with blisteringly hot weather? What is driving the wildfires, the soaring temperatures and those melting rooftops? These are tricky questions to answer, such is the complex nature of the planet’s weather systems. Most scientists point to a number of factors with global warming being the most obvious candidate. Others warn that it would be wrong to overstate its role in the current heatwaves, however.
“Yes, it is hard not to believe that climate change has to be playing a part in what is going on round the globe at present,” said Dann Mitchell of Bristol University. “There have been some remarkable extremes recorded in the past few weeks, after all. However, we should take care about overstating climate change’s influence for it is equally clear there are also other influences at work.”
Other factors involved in creating the meteorological conditions that have brought such heat to the northern hemisphere include substantial changes to sea surface temperatures in the North Atlantic.
And as global carbon emissions continue to rise and predictions suggest the world will be unable to hold global temperature rises this century to below 2C above pre-industrial levels, widespread heatwaves are very likely to get worse and become more frequent, scientists warn.
Nor is the problem of increasingly severe heatwaves confined to the land. “We have marine heatwaves as well – all over the globe,” said Michael Burrows, of the Scottish Marine Institute, Oban. “For example, there was a major marine heatwave that struck the coast of Australia last year. It devastated vast swathes of the Great Barrier Reef. More to the point, marine heatwaves are also becoming more and more frequent and intense, like those on land, and that is something else that we should be very worried about.”