It's a fact: our planet is warming—fast. Can we put the brakes on global warming, or is it too late to stop climate change from causing devastation?
On Friday, in more than 3000 protests worldwide, young people walked out of their classes in a youth-led climate strike. Estimates claim as many as 4 million people participated in the mass walk out, and their demands were clear: it’s time to take fast and decisive action to stop climate change so that our children have a future.
Over the past 100 years, the average surface temperature of the Earth has risen 1.62 degrees Fahrenheit, with most of that warming happening in the last 35 years. Ocean temps have risen by 0.4 degrees at the surface and sea levels have risen globally by 8 inches. Glaciers are retreating globally from the Alps to the Himalayas to the Andes, from Alaska to Africa. Greenland and Antarctica have seen hundreds of billions of tons of ice loss.
With the effects of climate change being so widespread and irrefutable, does this mean we are too late? Is there still time to slow it down?
Greenhouse gases still live in the atmosphere
Human contribution to climate change is mostly through the emission of carbon dioxide from burning fossil fuels. But even if we stopped emitting all greenhouse gases tomorrow, global temperatures would continue to rise. That’s because of something scientists call “thermal inertia.” Basically, greenhouse gases live on in the atmosphere. We’ll be paying the price for greenhouse gases we’ve already emitted decades into the future.
Even if we stopped emitting all greenhouse gases tomorrow, global temperatures would continue to rise.
The oceans remove the majority of carbon dioxide from the atmosphere over timescales of a century or so and have a stored heat capacity. In addition, the remainder of carbon dioxide, some 20-35%, is removed much more slowly and lingers in the atmosphere for as long as thousands of years. By contrast, methane (another greenhouse gas) only hangs out in the atmosphere for 10-12 years before it's lost to chemical reactions. So, if we stopped emitting all greenhouse gases tomorrow, we would still be in store for at least another 0.6 degrees of warming.
And that help we get from the oceans to absorb some of the excess carbon dioxide we produce is slowing, also. Ocean water already laden with carbon dioxide is hesitant to absorb more. Carbon-storing phytoplankton also can’t thrive without nutrients brought to them via the natural mixing of layers of ocean water—a mixing that doesn’t happen when top layers of ocean water are warmed by the atmosphere and then remain stagnant.
So what’s the point in trying if the writing is already on the wall? Well, without making any changes to our emissions, climate models predict that we are on track to see a temperature rise of 6 degrees Celsius. That’s a whopping 10.8 degrees Fahrenheit.
When is time up? Are we already too late to stop climate change?
Scientists have measured levels of atmospheric carbon dioxide by tracing carbon levels found in ice cores, trees, and even coral dating back 800,000 years ago. For millennia, those levels have fluctuated from as low as 160 parts per million to as high as 300 parts per million in an oscillating pattern. In 1950, however, the amount of carbon dioxide in the atmosphere reached 300 parts per million and never went back down. The level is currently around 400 parts per million.
We are now increasing the atmospheric levels so quickly that the natural processes that act as checks and balances on carbon dioxide in the atmosphere can't keep up.
So our environment is used to injections of carbon dioxide and has ways of removing it, as it has done for hundreds of thousands of years. But we are now increasing the atmospheric levels so quickly that the natural processes that act as checks and balances on carbon dioxide in the atmosphere—including photosynthesis and absorption by the oceans—cannot keep up.
Climate scientists have recommended that in order to avoid warming of 2.7 degrees (or more), which would mean a drastic difference in global climate including extensive food shortages and increases in extreme weather, we should aim to curb greenhouse gas emissions globally by 45% by 2030 and 100 percent by 2050. So, net zero emissions in 2050 is the target point, but by 2030, we must be well on our way toward making that goal a possibility.
Can we do what needs to be done?
Scientists first understood that increasing levels of carbon dioxide in the atmosphere would lead to rising global temperatures in 1896. We were already observing that temperature increase by the 1930s and watching Arctic ice levels fall by the 1960s. Given how long we've known what was in store, our lack of action so far does not inspire confidence.
We were already observing [global] temperature increases by the 1930s and watching Arctic ice levels fall by the 1960s.
Cutting carbon emissions to net zero will also likely require a sharp change in our way of life, including disruptive changes to our infrastructure as we switch to cleaner energy sources. But we’ve made such major overhauls before, like moving to indoor plumbing, paved roads, and, let’s not forget, the internet.
In addition to mitigating increases in global warming via lowered emissions, our strategy for facing climate change will also likely need to involve some adaptation. The roughly 8% of the world’s population that call coastal areas home may be forced to move inland as sea levels rise. Alternatively, for example, Miami is already installing flood pumps in preparation for more extreme storms.
So, while 2030 is soon, it’s not too late. We will need a globally coordinated response that links local to regional to national to international efforts to move toward cleaner energy sources and more sustainable daily choices. But the science is clear. We know what we have to do. And the future of our planet is worth it.
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