Climate Change, More Human Than We Thought

The Aztecs, affected atmospheric carbon levels? (Getty)

Global warming anyone? I ask as I don’t want to upset anybody. Forget it, I’m going to talk about it anyway.

Climate change is an important subject worthy of debate. But for a debate to develop into something constructive, all sides need to have some scientific merit. Clearly, if we listen to Leo DiCaprio, Al Gore and the world’s carbon-cutting politicians, we might be led to believe we are damaging the environment… hell, we might even be warming the whole planet through carbon emissions! So, strip the Hollywood glamour and political spin from the debate, does the global warming debate have any science linking human activity with increased global temperatures?

In a new study, focusing on Central and South America, scientists have uncovered possibly one of the earliest recorded cases of human-induced climate change, possibly amplifying (or even triggering) the Little Ice Age in Europe throughout the 16th century and beyond…

OK, so mankind’s addiction to fossil fuels and relentless consumption of the Earth’s natural resources are bound to have some consequences. However, there still appears to be strong resistance against the idea that carbon dioxide emissions may be contributing to global temperature increases. We know through exhaustive scientific studies that CO₂ is a very efficient greenhouse gas, this is a fact. However many believe that the evidence for human-induced global warming is fictitious, helping governments to pass new laws, boosting “green” revenue for countless carbon credit companies and bolstering the environmentalism of a few Hollywood celebrities.

CO2 trending with global temperatures (ice core samples)

Some of the climate awareness spin-offs may cloud the science behind global warming, but the science is there, global average temperatures wax and wane with atmospheric carbon dioxide content. Whether it be a volcano spewing millions of tonnes of carbon dioxide into the atmosphere or the advent of the industrial era, injecting carbon dioxide into the atmosphere is a sure-fire way of amplifying the Greenhouse Effect.

Note: Carbon dioxide is a greenhouse gas, providing a key component of our planets Greenhouse Effect. Without this mechanism, the Earth would not be able to retain the Sun’s energy, causing us to freeze. So, normally, the Greenhouse Effect is a good thing, but if it becomes too efficient at trapping the Suns energy, we overheat. This is why we need to control carbon dioxide emissions.

So, humans burn fossil fuels. We emit carbon dioxide. Lots of it. Is it any surprise that global temperatures are on the rise? Many dispute that global temperatures are even increasing, and that the climate isn’t changing in the slightest. Unfortunately, they are wrong. There is a very strong relationship between carbon dioxide emissions and global warming. And no, the Sun or cosmic rays are not behind this current upward trend toward increased average temperatures.

On reading Ethan Siegel’s Starts With A Bang, there appears to be another piece of evidence suggesting mankind has altered global climate for a lot longer than we realised.

In the 16th century, Europeans explored Central and South America. With them, they carried new diseases the native civilizations had never contracted before. 90% of the Inca and Aztec population was wiped out by smallpox and other illnesses over a very short timespan. Nearly 60 million people were removed from the planet by the year 1600, causing a 9% decline in global population. It turns out that this sudden loss of life had a global environmental impact.

The rainforests located in countries straddling the equator are often referred to as the “lungs of the Earth”. These vast regions extract CO₂ from the atmosphere and pump out oxygen. However, if you remove large swathes of rainforest, you damage natures ability to control carbon dioxide levels. Conversely, if you add trees to these regions, you improve natures ability to scrub carbon dioxide from the atmosphere. In short, tropical rainforests are our planets thermostat; by regulating carbon dioxide, global temperatures are regulated.

The Aztecs and the Incas were incredibly advanced, and this included their farming methods. 500,000 square kilometres of rainforest had been cleared for cultivation. So what happened when 90% of the population ceased to exist? Not only did the civilizations crumble, the rainforest began to encroach on farmland covering an area larger than the area of California.

Re-forestation boosted the regions natural ability to remove carbon dioxide from the air, thereby slightly lowering the atmosphere’s ability to retain the Sun’s energy. The authors of this new study estimate an extra 10 billion tonnes of carbon dioxide was removed by South American re-forestation. Global temperatures decreased by 0.1°C, possibly causing (almost definitely amplifying) the Little Ice Age that blighted Europe.

Accelerating deforestation in Brazil (AP)

If there are records dating this far back, it seems abundantly clear that the human race is more than capable of influencing our climate. So why is it so hard to believe we are not causing the current upward trend in global temperatures? Perhaps it is prudent to hear what science has to say about the subject and act accordingly. I personally think we also need some re-forestation in the tropics… However, it might already be too late.

Source: Starts With A Bang