• Matthew Blackett

A 'heatdome' and wildfires in skiiing country

It won’t have escaped many people’s attention that western #Canada (and the northwestern states of the US) are currently suffering from intense heat wave conditions. In fact, the poor town of #Lytton, British Columbia has been experiencing temperatures that are more usual in Dubai - 50°C - and that have been the highest on Earth for the last few days. And just to add to the problems caused by the excess heat, Lytton was evacuated on 30 June due to out of control #wildfires to the southeast (see image below) and at the present time, it seems that much of the town may be lost to these fires. To put into context how freakish these temperatures are, it is worth noting that Lytton is at the same latitude as the much more temperatute Plymouth, England.

Lytton, BC, and wildfires to the southeast (source: Planetscope image, from Planet, 30 June 2021).

The location of Lytton, British Columbia.

So why exactly are things so extreme in western Canada at the moment? Well there are a number of reasons for it. Continental parts of Canada (and indeed, of all land masses) see high summer temperatures because of an effect called #continentality. A large land mass rapidly heats in the summer, much more quickly than a body of water, producing such highs in temperature annually (and conversely, land masses will cool rapidly in winter, producing the extreme lows seen in Canada, Siberia, etc). The effect of continentality however, is seen every year; what is making it more extreme this year is what has been termed a #heatdome. Normally, the heat accumulations in continental regions such as #BritishColumbia will be relieved by winds that dissipate the heat and may result in a more 'normal' heat wave. In contrast, at the moment a high pressure system (descending air) is sat over British Columbia, kept in place by the #jetstream in an omega shape (see diagram below). This pressure system is trapping heat and allowing for its build up in this region. Being a high pressure system also means dry conditions, thereby providing no rainfall as a respite and creating kindling out of the land. We can only hope that rain arrives soon to help the fire fighters save what is left of Lytton.

The heat dome over British Columbia, kept in place by the encircling jet stream which has the appearance of the Greek letter omega (Ω) (Source: CBS News).

Even without wildfires, over 230 heat-related deaths have been recorded in British Colombia alone (the total will be many more when added to totals for other Canadian and American states, provinces and territories). Those at most in such extreme temperature scenarios are the very young and elderly and those with other chronic conditions. Community ‘cooling centres’ and ‘misting centres’ have been provided in many locations, so as to provide some relief to those without domestic cooling systems. Residents are also being advised to check on vulnerable neighbours and friends. Over and above the tragic impacts on health and death rates, the extreme heat in Pacific Canada and America has caused chaos to residents on the move. It has buckled highways and even melted some public transport power cables.

Many will of course be wondering what influence #globalwarming and #climatechange may be having on this phenomenon. Whilst a direct link would be hard to prove categorically, President #Biden announced on Tuesday 29 June 2021 that the heat wave on US-west coast (and associated wildfires) were tied to climate change. And Scientists predict there will be more of these sorts of extreme events, including more wildfires, as climate change continues.

There is probably not much we can humanly do to stop our climate from continuing to change, but we might be able to slow the changes down. Indeed, increased understanding of the term #climateemergency throughout many societies might be the call to action that is needed to alter human activities and lessen longer term climate changes and their impacts. What is needed are more scientists and engineers to work on our energy transition to renewable and lower impact energy generation systems. Let’s hope it’s not too late and that such events don’t become all the more common. For now, all we can do is watch and hope that Lytton is spared from complete destruction.