Contrary to popular belief, Earth’s climate has not always been the same; just in the last 650,000 years there has been several cycles of temperature rise and fall due to small changes in Earth’s orbit and the amount of energy Earth receives from the Sun. However, in the past 50 years, Earth’s climate has changed dramatically, and scientists predict this rapid change in climate to be the result of human activity within the past century with greater than 95 percent probability . Satellites orbiting Earth have enabled scientists to collect many different types of information about our planet’s climate on a global scale while allowing scientists to pinpoint the direct cause for this drastic change in Earth’s climate. Many scientists can agree that the main cause of this warming trend is due to the human expansion of the “greenhouse effect”, where Earth’s atmosphere traps heat radiating gases which in turn causes a global temperature rise. Certain gases, such as carbon dioxide, methane and nitrous oxide, trap heat in Earth’s atmosphere. While these gases have always been present in Earth’s atmosphere, the burning of fossil fuels such as coal and oil has dramatically increased the amount of greenhouse gases in our atmosphere, as carbon dioxide levels have risen from 280 parts per million to 400 parts per million over the past 150 years . While the consequence of changing the natural composition of our atmosphere are difficult to predict, certain effects seem likely such as:
. An average increase in Earth’s temperature.
.Warmer conditions resulting in more evaporation and precipitation, causing some regions to be wetter and other to be dryer, therefore resulting more a extreme climate.
.A larger greenhouse effect will warm oceans and melt glaciers, resulting in sea level rise.
.Higher temperatures and shifting climate patterns may change the areas where certain crops grow best.
There are four major factors affecting long-term climate change: changes in axis tilt, changes in reflectivity, solar brightening and changes in greenhouse gas abundance. Small gravitational tugs from the Moon and other planets can cause the tilt of a planet’s axis to change over long periods of time, therefore changing the angle that sunlight hits Earth resulting in global climate change. Due to the fact that the Earth’s axis tilt has not changed in the past 150 years, it is evident that changes in axis tilt is not the cause of our current climate change. Similarly, a change in a planet’s reflectivity, due to factors such as increased cloud cover, has remained relatively constant over the past century therefore does not contribute to our present global warming. Theoretical models of the Sun also tell us that the Sun has gradually brightened with age, therefore increasing the amount of solar energy reaching Earth. Studies have shown that solar variability has played a vital role in past climate changes, such as a decrease in solar activity is thought to have triggered the last Ice Age over 7,000 years ago. However, it is evident that the current climate change cannot be explained by changes in solar energy due to several reasons. Since 1970, the average amount of solar energy received by Earth has remained relatively constant. Similarly, if global warming were caused by increased solar energy, then scientists would expect to see warmer temperatures in all layers of the atmosphere. Instead, they have observed cooling in the upper atmosphere and warming in the lower atmosphere, which is a result of greenhouse gases trapping heat in the lower atmosphere. Finally, climate models that include solar energy are unable to reproduce the observed temperature rise over the past century without including the effect of a rise in greenhouse gases. Therefore, it is evident that the dramatic climate change we are experiencing now is due to increased abundance of greenhouse gases in our atmosphere, and the data points to mankind as the cause.
Anyway, I could probably go on and on about this but… climate change is real! Believe it! There is hope, though. Debunk the myth, tell your neighbors of this pressing issue and and as a global community we can come up with ways to reduce our carbon footprint and save our planet. 🙂