The fire danger models should be expanded

FIRES have been breaking out in various parts of the world and some people blame climate change, with its more extreme weather conditions. Looking at gardening sites you will discover that hot, dry winds can cause injuries and death to some parts of plants.

Are these dry, dead parts of plants an invitation to fire? Some researchers divide the wind speed by the relative humidity to get drying power, because a low relative humidity and high wind speed will give great drying power in agreement with a large value for speed/humidity.

But climate change means there is more drying radiation about. This is because the high temperature sun gives out high frequency electromagnetic radiation in the form of light and so on, and this penetrates the atmosphere.

It warms the earth (yes, the light that we see warms the earth) and the earth, being much colder than the sun, radiates electromagnetic radiation at a much lower frequency. The carbon dioxide can keep this lower frequency radiation in and so we have increased radiation.

Why not see if there is a correlation between drying wind and fires? The South African Lowveld Fire Danger Index does not expressly take radiation falling on plants into consideration and I have formulated a “radiation index” which you can see at Fire Danger South Africa on Facebook.

I think fire danger models should incorporate solar radiation and the cumulative drying effects of wind. Perhaps because of changing radiation, fire danger models need a small amount of adjustment.