climate change
Toronto Now reporter Zach Ruiter has called the imminent extinction of mankind based on all the different climate scare stories he has read.
Are we headed for near-term human extinction?

Recent studies suggest it is irresponsible to rule out the possibility after last week's "warning to humanity" from more than 15,000 climate change scientists


A "warning to humanity" raising the spectre "of potentially catastrophic climate change... from burning fossil fuels, deforestation and agricultural production - particularly from farming ruminants for meat consumption," was published in the journal BioScience last week.

More than 15,000 scientists from 184 countries endorsed the caution, which comes on the 25th anniversary of a letter released by the Union of Concerned Scientists in 1992, advising that "a great change in our stewardship of the earth and the life on it is required, if vast human misery is to be avoided."


[Several speculative climate scare stories - methane, ocean acidification, ice free arctic, decline of sulphate aerosols from coal]


The take-away

Out of control climate change means feedback mechanisms may accelerate beyond any capacity of human control. The occurrences discussed in this article are five of some 60 known weather-related phenomenon, which can lead to what climate scientist James Hansen has termed the "Venus Syndrome," where oceans would boil and the surface temperature of earth could reach 462 degrees Celsius. Along the way humans could expect to die in resource wars, starvation due to food systems collapse or lethal heat exposure.

Given all that remains unknown and what is at stake with climate change, is it irresponsible to rule out the possibility of human extinction in the coming decades or sooner?
The simplest argument against Hansen's boiling oceans fallacy is the Earth's geological history and a bit of common sense.

Past CO2 levels were much higher than CO2 levels in today's carbon dioxide starved world. The Cretaceous, the final age of the dinosaurs, averaged 1700ppm CO2 - over 4x today's CO2 levels. If CO2 was capable of driving the oceans to boiling point, this catastrophe would have already occurred long ago.

Humans would survive any lesser global warming disaster. Imagine for a moment we're all wrong, that regional Northern temperatures soar by 27F (15C) in the next century. Britain, Northern Europe and the Northern states of the USA would still be colder than the current temperature of my subtropical hometown. Some already hot places might become inhospitable, but vast regions of the world - Northern Canada, Siberia, Greenland, Antarctica - would actually become a lot more benign for habitation by tropical species like human beings.

Whatever climate change the next century brings, and the evidence to date is "not a lot", climate change will not cause the imminent extinction of humanity.