Heat wave: Q & A with the Centre for Climate Change's Altaf Arain

July 21, 2011

    Extreme heat waves such as the one that has temperatures soaring across southern Ontario recently could become more frequent due to the effects of climate change, says the director of McMaster's Centre for Climate Change. Photo by flickr.com/photos/jalalspages.
Extreme heat waves such as the one that has temperatures soaring across southern
Ontario recently could become more frequent, says
the director of McMaster's Centre for Climate Change.

According to Altaf Arain, global climate models predict that we'll experience more
extreme weather patterns in the future as a result of the Earth's climate gradually
becoming warmer. The associate professor and associate director of the School of
Geography and Earth Studies answers questions about the current heat wave below.

Is a heat wave such as the one we're currently experiencing considered "normal"?

We are in the midst of an extended heat wave, with temperatures expected to peak
Thursday. July this year has been unusually warm and dry. It's not a normal weather
pattern for this time of the year because both heat and drought have occurred
simultaneously, though a similar event was observed in 2005.

Can we expect to experience heat waves more frequently in the future?

Yes, we may experience more severe and frequent warm/cold temperatures as well as
drought and flooding events in the future. These trends have been observed in various
regions across the world in recent years. An increase in extreme weather patterns has
also been predicted by climate models analyzing future climate change.

What are some of the effects of going through a long period of heat and lack of rain
on our local environment?

Heat waves may affect the health of seniors and children who are more vulnerable to
these events. They may also exacerbate pre-existing health conditions in some people.

A lack of rain may impact vegetation growth and ecosystem health as well. For example,
forest ecosystems may lose more carbon, as compared to their typical carbon uptake,
during heat waves. Farmers in southern Ontario will also be impacted due to reduced
crop yields and the high cost of irrigation for certain crops.

Do we know how long this heat wave will last?

Things should start to ease up in the next few days, but we cannot accurately predict
weather patterns beyond a few days.