I would like to respond to a letter written recently in this paper about climate change and list a few things we know, and don’t know, more from a scientific perspective.
We know the parts per million of CO2 in the atmosphere have increased the last 300 years, or preindustrial era timeframe, from 280 PPM to 408 PPM current. We know CO2 is a greenhouse gas that has the ability to deflect back outgoing radiation thus producing warmer conditions. We don’t know all the consequences of such an effect, such as increased cloud cover from higher evaporation rates which have the opposite effect. We do know earth’s temperatures have been steadily increasing recently, which coincidentally coincides reasonably well with increased CO2 emissions, but we don’t know the extent of all the other potential contributors.
We know the earth has been considerably warmer in most of its existence. The Mesozoic Era, 250-65 million years ago, which supported the dinosaurs, was generally much warmer, more humid and very tropical. In the Cenozoic Era, from 65 million years ago to current time, the earth became generally much cooler and drier. In more recent time, the Quaternary period, the northern hemisphere has rotated in and out of ice ages.
We currently live in a glacial interlude. We know from pollen grains that 4,000 years ago the climate in Central Minnesota was slightly warmer than is currently. We know one of the glacial interludes produced sea levels about 15 feet higher than present. But we don’t know how gradual these changes were or whether these changes occurred in intervals of extreme fluctuations.
In relationship to droughts, we know higher temperatures can increase evaporation rates, which can lead to more severe droughts. We also know an increase in evaporation levels can also lead to heavier isolated rainfall amounts. But what we don’t know is how this will play out in the overall weather patterns. We don’t know how many droughts have been avoided completely, or reduced in intensity, because of higher rainfall levels due to increased evaporation rates. We also know from history that droughts have been commonplace occurrences.
We also know droughts can exacerbate wildfires, but we also know most of the Upper Midwest was originally the largest prairie land in the world, which requires frequent burning for sustainability. We also know woodlands, such as the great Hinckley fire, and more recently Yellowstone, require burning for natural regeneration.
In relationships to extinctions, no doubt changing weather pattens can play havoc on species, but many other human intrusions could be playing even larger roles. We as humans, whether you believe in evolution or creation for our existence, our design gives us two unique traits when compared to other mammals. Our lack of fur or hair, and our high disproportionate number of sweat glands, allow us to survive and even thrive in very warm climates. We also know a warmer climate will increase production in many higher latitude locations around the world, and very possibly here in Central Minnesota. We also know higher carbon dioxide levels encourage plant growth.
From an opinion viewpoint, please be more objective in your reporting, especially now around election time. Because everyone does not hold the same opinion, please be respectful of other diverse ideologies because facts can be elusive. The article on climate change was very derogatory to people who question all the facts on that subject. The human trait of overreaction is a survival instinct intended to protect us from predators and potential harm, e.g. when we hear the leaves rustle when traveling through a forest, it is better to overreact and flee then to see if it is a harmful predator.
Overreaction also makes us vulnerable to fear tactics, which can prove to be very convincing when only reporting one side. Social media is full of such tactics, but you can do better. I know it is only the editorial page but please try to report and represent both sides more fairly and equally for the benefit of all.
