So, it's over. 2020 has finally slipped into the annals of history. Unfortunately, it's left us with an ongoing plague. Here in the UK, we're currently in our third Covid lockdown, and so far 2021 doesn't feel much different from last year.
Nonetheless, 2020 is in fact over. And for all the political, social and economic chaos that it brought, climate change was still very much with us. So, without further ado, here is a review of the climate.
If you've paid any attention to the news on climate change recently, you'll probably have heard that 2020 was the joint hottest year on record. But what does that actually mean? I know, I know, it seems simple and self-explanatory, but it's actually a little more complicated than it sounds. For one thing, when we talk about global temperature records, it's important to understand what is being measured. Temperatures at the surface of the planet are different from temperatures in the oceans, which are different from temperatures in the atmosphere, and of course, these vary by depth and altitude.
respectively. But generally, when you see reports of the hottest year on record, they are referring to surface temperatures. You know, the bit where we live.
And of course, there are always uncertainties in actually recording these temperatures. After all, we don't have thermometer readings for every square inch of the planet. As a result, there are small disagreements between the major global datasets. NASA, for example, has 2020 as the hottest year on record by a tiny margin, but NOAA, Berkeley Earth, Copernicus ERA5 and the Hadley Center all put 2020 as a close second behind 2016. So if most of the datasets agree that 2020 was cooler than 2016, then why do so many reports claim that it was the joint warmest? Well, these datasets can only record temperature to within an accuracy of 0.05 degrees, but the difference between 2020 and and 2016 was less than that in all of them.
This means that it's impossible to say with any deal of certainty which was hotter, and that's why it's officially a tie. But whether 2020 was the hottest or second hottest year on record is almost a moot point. In 2016, surface temperatures were boosted by a massive El Niño event, a natural warming process driven by the Pacific Ocean.
But 2020 had no such boost, and yet surface temperatures still equalled those of 2016. It would be a bit like Like if two athletes came joint first in a sprint, but one of them had used a bunch of steroids and the other was totally natural. It's not really a fair comparison, and the natural athlete really shouldn't be competitive. The fact that 2020 and 2016 were so close is testament to the warming that occurred in the years between them. Indeed, 2020 capped off the hottest decade ever.
recorded. But remember, these are only surface temperatures, they only tell us part of the story. Over 90% of recent warming has occurred in the oceans, and when we look at ocean heat content, 2020 is easily the hottest year on record. Interestingly, by this metric, 2016 was only the sixth hottest. This is because the El Nino event which helped 2016's surface temperatures be so warm transferred heat out of the oceans and into the atmosphere, warming the surface at the expense of the oceans.
But regardless of how you measure global temperatures, the warming trend is still the same. is the same. Every decade since the 1980s has been hotter than all the decades that came before, and the last year to record surface temperatures below the 1951 to 1980 average was 1976, the year that gave us Rocky, the first space shuttle, and this absolute banger. You've got to love Elton.
But what that means is that if you're under the age of 44, every single year of your life has been warmer than average. But despite this undeniable warming trend, the climate disinformation machine is still pumping out utter nonsense, like this, possibly the dumbest take on recent climate trends. I mean, they're not wrong, but it's the most shameless example of cherry picking I've ever seen, and I've seen a lot of cherries picked over the years.
It wasn't long ago that skeptics would claim that there had been no warming since 1998, and for a period of about 15 years, give or take, this appeared to be true. Between 1998 and 2012, there was only the slightest warming, and this period became known as the global warming hiatus. But this hiatus was only present if you ignored the warming trend in the oceans, and it ceased to exist altogether for the years after 2012. But while you'll find many sceptics who will harp on about those 15 years, you'll be hard-pressed to find any who will talk about the most recent 15-year period.
This is because, since 2006, the rate of warming has been two times above the long-term average as the hiatus was below it. So sceptic logic would have us concluding that warming was accelerating. Of course, it goes without saying that 15 years is too small a period of time to draw any definitive conclusions about long-term climate trends, but it's worth keeping in mind the next time someone brings up the so-called hiatus.
But let's get back to 2020. How have these record temperatures affected the climate? Well, if you cast your mind back to the beginning of last year, back before the plague was upon us, you might remember that Australia was on fire for several months. Then… Later in the year, the same thing happened down the entire west coast of the United States.
And in the Amazon. And in Siberia. In fact, Siberia and the Arctic region saw some of the most anomalously high temperatures on the planet. While the Earth as a whole was about 1.3 degrees warmer than the pre-industrial era in 2020, Siberia was 5 to 7 degrees warmer than its regional average for almost the entire year.
That's a seriously large temperature anomaly, which is nerdspeak for way too hot. Indeed, the Arctic is also one of the fastest warming regions on the planet, and 2020 saw its second lowest sea ice covering in recorded history. Indeed, a recent study found that between 1994 and 2017, the Earth as a whole lost a total of 28 trillion tonnes of ice, and the rate of ice loss rose by 57%. If you're struggling to comprehend that, well, I don't blame you. It's colossal.
And, unsurprisingly, it's also contributed to ongoing sea level rise. And if you're wondering whether all the melting and all the burning might have something to do with all the, you know, extra heat, then I can tell you that yes, yes it does. The fires we saw in 2020 were abnormally intense, and the amount of ice we're losing is astronomical.
Not only do numerous studies demonstrate a clear link between warming and ice loss and warming and wildfires, the climate effects of 2020 were predicted decades ago by climate scientists. In 1972, for example, Russian scientist Mikhail Bediko predicted an additional one degree of warming by 2019, and the disappearance of about 50% of Arctic multi-year ice. As of 2020, there has been 0.98 degrees of warming and Arctic multi-year ice has declined by 46%.
The warmth of 2020 was also accurately predicted by climate models, and the intensification of wildfires was listed as one of the key risks to North America by the IPCC AR5 report. But hey, what do the scientists know? So it's clear that 2020 was a record-breaking year and you may well be asking yourself if this almost literal dumpster fire is the new normal But no, it's not as long as atmospheric co2 continues to rise the earth will continue to warm and the climates will destabilize further and further That's not a statement of politics or opinion. That's a fact of physics This isn't the new normal.
This is about as good as the climate is going to get until we reach carbon neutrality. Sure, we'll have a few years richer cooler, 2021 is likely to be one of them, thanks to a developing La Nina event. But over the long term, it's going to get hotter. 2020 might be the hottest year in the historical record so far, but without significant climate action, it's likely to be one of the coolest of the 21st century.
It's not going to magically start getting cooler on its own. Well, not unless there's a catastrophic meteor impact or world-ending volcanic eruption. Yeah, let's not joke about that. But for all its heat records, fires and melting ice, 2020 has shown us a glimmer of hope.
Many of you are probably wondering about the elephant in the room. His name's Gilbert, and he's got the one thing you can't avoid when talking about 2020. COVID. I mean, he hasn't got Covid, he's just got this, but you know what I mean.
Anyway, you've probably noticed that the pandemic has changed the way we live. I mean, I've spent nearly the entire year in this room. In any case, you may be wondering how, if at all, lockdowns have affected the climate. So, let's find out. Unsurprisingly, global CO2 emissions fell considerably in 2020, with the latest estimates from the Global Carbon Project suggesting a fall of 2.4 gigatons.
tons of CO2, a drop of about 7% compared to 2019. This is the largest absolute drop ever recorded, and the largest relative fall since a chap called Adolf decided he fancied a chunk of Poland. It's also the first time that global emissions have fallen since 2009, the year after some sneaky bankers ruined the global economy. But before you start celebrating this drop in emissions, it's important to remember that they have only fallen to the levels of 2011, which is still way too much for the environment to absorb.
This means that atmospheric CO2 still rose by 2.5ppm in 2020, which is almost the same as the increase in 2019. The bottom line is that CO2 is continuing to accumulate in the atmosphere, and current atmospheric levels are 48% higher than the pre-industrial era and at their highest point in literally millions of years. However, there are reasons to be optimistic. The drop in emissions combined with an increasing global will to decarbonise and ever cheaper, more reliable and more competitive renewable energy sources means that it is possible that emissions may never again reach the levels of 2019. Indeed, the 2020 edition of BP's annual outlook suggests that 2019 may have been the peak in oil demand, which is a major revision down from their previously published estimates. And yes, that's BP as in the oil and gas company, not some environmentalist radicals. 2019 was also the first year since 1885 that the energy generated by renewables surpassed the energy generated by coal in the US, and the pandemic has only accelerated its decline.
For all its misery, COVID-19 has presented us with a unique opportunity to lock in long-term emission reductions and to seriously mitigate the effects of future climate change. But let's not get complacent. There is every chance that we'll cock this up.
When emissions fell after the 2008 crash, they quickly bounced back and resumed their upward trend. 2020 was many things to many people. Misery and boredom, mostly. But ultimately, we can choose what we make of it.
In some ways it was a warning. It revealed the fragility of our societies and economies, that no nation can deal with global problems in isolation, and that the effects of climate change are already upon us. But it also presents an opportunity to capitalise on the emission reductions that have been forced upon us, and mute the effects of future climate change.
We can choose to act decisively. Or We can do what we've always done nothing. We can ignore and undermine science, delay decisive action, blame China and fall back on delusional optimism.
We can find a million excuses to rationalise why inaction is the best option. Or we could learn from 2020. Inaction, delay and science denial costs lives. So, perhaps above all else, 2020 should be a lesson.