I am writing this in response to the numerous letters to the editor recently (e.g. letter on Feb. 17 by Ed MacDonald) that have asserted that human-induced climate change does not exist. The most disturbing parts of these opinions are the claims that there is no scientific evidence that humans are influencing climate change. These writers may have their opinions, but the truth of science is that it is (among other things) factual, evidence-based and peer-reviewed many times over. There are no proofs in science, only well thought out and revised theories based on our observations of the world around us.
The efficacy of climate models may be debated, results of single studies can be disputed, and there will always be some uncertainties and error associated with science results. However, the Intergovernmental Panel on Climate Change has reviewed thousands of published scientific results over the last 30 years and has stated with high certainty the following: “Scientific evidence for warming of the climate system is unequivocal”.
Many arguments against climate change state that over the course of geological history there have been many warming trends due to various cycles, which is correct. Left unsaid is the fact that the current warming trend has a high likelihood to be the result of human activity and is proceeding at a rate of temperature change that is unprecedented across geological record. Carbon dioxide levels – going back 800,000 years – have never exceeded 300 parts per million. It is now over 410 parts per million.
The authors also state that carbon dioxide is not important to worry about. Based on scientific discoveries made in the 19th century and earlier (molecular properties of gases and thermodynamics) it is well established that CO2 is more effective at trapping heat when in higher amounts in the atmosphere. Among scientists there is no question that increased levels of greenhouse gases like CO2 cause the Earth to warm in response. Regarding the supposed “no measurable response of temperature rise” – global weather sources report a rise of around 1.5 °C since the 1800s and the five warmest years on record have been since 2010.
Despite the mounting evidence of increasing global temperature rise, warming and acidification of oceans, increasing catastrophic weather event severity, increasing fire frequency, melting of sea ice and glaciers at an unprecedented rate – some people are still finding it far easier to deny the evidence than to accept it and try to do something about it. Examples of climate change present themselves all over the world – go to the Arctic and speak to the communities about the melting permafrost changing their lifestyles, or talk to the Aussies about the condition of their coral reefs and fires ravaging their lands. People today are mortgaging the security of future generations with constant denials, lack of action, and indifference. We need to come together not with “hysteria”, but with non-partisan conviction and action to mitigate the effects of climate change.
Owen Smith, St. Albert