“IT’S NOT THE FIRST TIME CLIMATE IS CHANGING, SO CALM YOUR TITS…”
On what was probably a nice, warm, and sunny day many millions of years ago, the inhabitants of Earth received a most unexpected visitor. If you were a Brachiosaurus lazily munching on vegetation, or a T. rex stealthily stalking prey on the Mexican peninsula, one moment would have been clear skies above you: the next moment; a ball of fire, brighter than the sun hurtling to the ground. And the next moment: utter and instantaneous destruction for a radius of hundreds of miles.
Approximately 66 million years ago, an asteroid about 10–15 kilometers wide struck Earth off the coast of the Yucatan peninsula, Eastern Mexico. It made quite the touchdown, creating a crater (the Chicxulub crater) more than 185 kilometers in diameter. The impact created a fireball that destroyed all life within 1000 kilometers in a few seconds. It also generated earthquakes and tsunamis that no doubt killed many more creatures.
The immediate effect of the asteroid strike yielded deadly fireworks. But it was the long-term effects that really did a number on the inhabitants of Earth at that time. Ash and debris from the asteroid’s impact would have circulated all around the globe, producing days with the light quality of twilight- this may have lasted for years. This pervasive dimness meant that photosynthesis would have come to a near halt.
A nuclear winter lasting for a few years would have expectedly followed. Geologists estimate that upon impact, the asteroid would have released a billion upon a billion tons of CO, CO2, and CH4. This meant that Earth’s climate would then have been hit by a one-two combo of a very long winter and then rapid global warming. Paleontologists estimate that up to three-quarters of the life forms of that era were destroyed- the Cretaceous-Paleogene (K-Pg) extinction event. And this did not happen directly due to the asteroid’s impact, but the climate change that followed.
That incident was probably Earth’s most dramatic climate change (at least until now). Geological records tell us that Earth’s climate has alternated from being a frigid ice-box to becoming a steaming sauna. These climate changes were usually due to alterations in the Earth’s course around the sun that increased (or decreased) the heat it received from the sun. Or due to massive volcanic eruptions. So if Earth’s climate has repeatedly changed, why the entire furor?
One of the things that make the current climate change worrisome is how fast it’s happening. Unlike the previous episodes of climate change which typically occurred over thousands of years (and in cycles of about every 100,000 years), this current episode is happening so fast. In a natural cycle, Earth typically warms by about 0.5°C every 1000 years. But since the 1800s (the onset of the Industrial Revolution), Earth has warmed by 1°C. That’s 1°C of warming in just over 200 years! Isn’t that staggering?
Another reason for all the “noise” and concern you see is because of WHY Earth is warming this fast. Climate change has three main drivers: solar variability, volcanic eruption, and alterations in Earth’s carbon cycle. In the last couple of hundred years, only one of the above three parameters has altered sufficiently to warrant the amount of warming we’re currently experiencing: alterations in Earth’s carbon cycle.
The only significant activity in the last few thousand years that could have upset Earth’s carbon cycle is man’s dependence on fossil fuels. CO2 is one of the greenhouse gases that help Earth retain heat. And we’ve pumped so much CO2 into the atmosphere thanks to our heavy dependence on fossil fuels. In the past 200 years alone, CO2 levels in our atmosphere have risen by over 40%.
Just like the climate change that fueled the K-Pg extinction event, this episode of climate change is happening too fast, and should this trend continue, we would have the same chance the dinosaurs had to adapt to their rapidly changing climate- none. And unlike the dinosaurs that were not complicit to what befell them, the current trend of climate change has man’s sooty fingerprints all over it. We’re essentially reaping what we’ve sown.
Again, unlike the hapless dinosaurs, we’re well able to do something about the threat of climate change before it’s too late. Fossil fuel use is the largest source of CO2 emission. Developed countries must take the initiative and massively reduce our dependence on fossil fuels. Everyone must be involved in the efforts against climate change. We all must find ways to reduce our “carbon footprint.”
All significant climate changes, including the “very natural” ones, have proven to be disruptive to every living species. Ignorance, denying the facts, or playing at nonchalance will not save us from the coming impacts of climate change. We must take action and do so now.
