“I’m not a denier. I don’t doubt that climate change exists,” said Sarah Palin in 2008. “No one has proven that these changes are caused by anything done by human beings via greenhouse gases. There’s no convincing scientific evidence for man-made climate change. The climate has always been changing.”
“I believe there’s change, and I believe it goes up and it goes down, and it goes up again,” said Donald Trump in a 2015 interview. “And it changes depending on years and centuries, but I am not a believer, and we have much bigger problems.”
“Sure, the climate is changing,” said Marco Rubio in a 2016 presidential debate. “And one of the reasons why the climate is changing is because the climate has always been changing. There has never been a time when the climate has not changed.”
… and all three of them are half-right. The climate has always been changing. They are dangerously wrong, of course, in saying that the concerning and rapid climate change we talk about today is not caused by humanity’s ever-increasing greenhouse gas emissions — but let’s take a look at the correct half of what these politicians have said about global warming …
Climate change is a tale as old as the Earth. In the Cretaceous Period, 65 to 145 million years past, the Earth was much warmer, and tropical jungles grew in the Arctic Circle. During the most recent Ice Age (one of the many in Earth’s history), temperatures dropped precipitously and glaciers crawled across the globe.
The climate on Earth has never been stable, it’s true, but we are here now – and this is what Palin and many other right-wing politicians fail to take into account when they use this “the climate has always been changing” argument against policy.
Humans being here now makes all the difference, for two primary reasons — one, the climate change that is happening now is our fault, and thus everything that happens as a result – the great suffering of humanity and other species, the death of ecosystems and painful pruning of ecology — is our fault as well, the direct consequences of our selfish and ignorant actions. Two, human-driven climate change is happening at an unprecedented rate that will jeopardize not only our children, but the future of most life on Earth.
The forces behind climate change can be separated into at least three fundamental categories.
The first is tectonic processes, stimulated by the internal heat of Earth, that cause changes to its surface, ocean currents and volcanic eruptions (which affect temperature and carbon dioxide levels in the atmosphere).
The second is the changes in the energy level of the sun and to Earth’s orbit around the sun (which alters the amount of solar radiation the planet receives).
The third is anthropogenic climate forcing, which includes the release of greenhouse gases (like carbon dioxide and methane) into the atmosphere as a result of industry, farming and technology.
Before humans began to invent technologies and processes that release greenhouse gases into Earth’s atmosphere, climate change happened slowly as a result of the first two categories. Since anthropogenic climate forcing began, however, change has been driven overwhelmingly by human-driven activities — a change far too rapid for a great many species (including our own) to adapt to.
At this particular time in Earth’s history, we are lucky — the Earth’s climate is comfortable in many places and thus humans can live quite comfortably. So the question at hand is not if the climate has always been changing (for we know the answer is yes), but rather — what makes this time different for us?
We are children of the last Ice Age, and as a consequence, we and our civilization are closely adapted to the cool planet we know. We should be afraid of this calamitous climate change of our own making. We must take action, before the chance of reversing our impacts recedes beyond our reach.
Some versions of humanity have existed on the Earth for millions of years. We have slowly evolved to our present state, with very recent technologies allowing some of us (although not a large percentage) to live in unprecedented comfort. It is true that humanity has survived through extreme climate fluctuations like the last Ice Age, which peaked 20 to 25 thousand years ago.
However, anthropogenic climate change is in the opposite direction, causing the Earth to heat and the melting of both mountain glaciers and polar ice caps. We are simply not adapted to this heat. Earth’s hottest periods occurred long before humanity evolved, and heating from anthropogenic climate forcing will affect us in ways that humans have never experienced.
On a global scale, this hot earth will cause massive food shortages due to lost agriculture, melting ice will cause city-destroying water-level rising, and the impacts on natural ecosystems threaten a myriad of disastrous results. It is human-driven climate change doing this, and human responsibility to stop it.
