Climate change has once again been proven not to be triggered by natural factors, in the seemingly never-ending “man versus nature” controversy.
The findings have been featured on Monday, February 1, in the Journal of Climate, and have been based on research led by Patrick Brown, PhD student at Nicholas School of the Environment, from Duke University, in Durham, North Carolina.
Brown collaborated with experts at NASA’ Jet Propulsion Laboratory, and determined that if it weren’t for human activity, temperatures around the world wouldn’t be perturbed as they are nowadays, and instead oscillations from year to year would be virtually insignificant.
The analysis was based on global climate modeling (GCM) simulations, which were meant to assess climate sensitivity.
Namely, using this technique, scientists were able to measure the effect of various factors, such as anthropogenic activities, natural carbon dioxide and other greenhouse gas emissions, solar irradiance (the amount of energy that the Sun sends to our planet’s outermost layer of atmosphere) etc.
Research was further aided by data collected thanks to Earth observation satellites, which monitored the levels of radiant energy that our planet has been receiving and ejecting back into space in the last 15 years.
What experts discovered is that Earth ceases to regulate its global temperature effectively, under the influence of anthropogenic climate change.
Normally, an effect known as the Planck response causes our planet to reflect more energy through the exosphere into outer space as its overall temperature increases.
This has a cooling effect on Earth, allowing it to keep its surface temperature more stable, as inordinate amounts of heat are being released so as to curb the greenhouse gas effect.
Previously it had been noticed that in some regions of the world the Planck response is rendered fruitless by naturally occurring weather patterns.
For instance, clouds can send solar energy back into outer space, but they also cause heat to accumulate in the atmosphere, so any perturbations in cloud cover can result in an increase in temperature.
Similarly, a rise in water vapor can cause more clouds to form, therefore rising our planet’s albedo (amount of solar energy reflected into space), but it can also heighten the greenhouse effect, resulting in even more significant warming.
Changes related to snow and ice distribution can also accelerate climate change, because as the protective frozen covering melts, Earth’s land and oceans can trap more heat, causing overall temperatures to soar.
Now however, study authors have come to the conclusion that there are other factors at play also, which prevent naturally-occurring warming to have any distinguishable effect on global climate.
As explained by Dr. Wenhong Li, assistant professor of climate dynamics and environmental engineering at Duke University, due to atmospheric movements, thermal energy tends to be more evenly distributed when such temperature-rising phenomena occur.
More precisely, the heat resulting from natural weather patterns usually is usually spread across cooler areas, being transferred from regions such as the tropical Pacific towards the geographical poles, where its effect becomes much more indiscernible.
Based on these findings, study authors believe that human activities remain the main driving force behind global warming, while natural occurrences have a much more limited impact.
As a result, greater efforts should be made in order to reduce anthropogenic climate change, resulting from the burning of fossil fuels and deforestation.
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