Hello I'm Michelle Tapper with the Latest from Science. There’s been a
huge reduction in greenhouse gas emissions since the COVID-19 pandemic was declared in
March this year.
As multiple countries began lock downs and border closures, energy demands around the
world were reduced. Planes stopped flying, people stayed at home and there were less
cars on the road.
So what was the impact on our carbon dioxide emissions?
Well, here to explain the details is Academy Fellow and one of Australia’s leading climate
scientists, Professor David Karoly. He is also the leader of the Earth Systems and Climate
Change Hub at the CSIRO.
Hi David, thanks for joining us. Hi Michelle.
How significant have the changes been in the reduction of greenhouse gas emissions since
lockdowns began? The reductions have been very significant.
There have been major reductions in carbon dioxide emissions associated with burning
fossil fuels from a number of different sectors because of the massive reductions in economic
activity and transport usage around the world. Research has just been released with data
from 69 countries that represent 85 per cent of the world population. What does that research
show? This research shows what's happened in April
and May, early May, in terms of the reductions in emissions, essentially across the world,
but it focuses on the changes in fossil fuel related carbon dioxide emissions. Carbon dioxide
is the biggest contributor to increases in greenhouse gases in the atmosphere associated
with human activity and they have plummeted. In early April, the emissions have fallen
by about 17 per cent on a daily basis relative to the previous year, 2019. And that 17 per
cent reduction in emissions is equivalent to how emissions were way back 14 years ago
in 2006. So there was a major reduction in emissions.
So those are some pretty significant reductions and we've seen some huge impacts around the
world, like less pollution in big cities, even clean water in places like the Venice
canals. What other improvements have we seen globally?
Look, what we've seen associated with the reductions in using fossil fuels for producing
electricity—coal fired power stations have essentially produced less air pollution. Road
transport is the other major sector that's led to reductions in fossil fuel use for cars,
for trucks, for road transport. And that has meant less air pollution. And what we've seen
is around the world, in addition to the reductions in greenhouse gas emissions, we've also seen
major improvements in air quality or reductions in air pollution, particularly in urban areas,
but also in areas where air pollution occurs associated with, for instance, generating
electricity or associated with industrial activity.
Now we know that many countries are still in lockdown, but in some countries like Australia,
restrictions are being eased. Do you think these short term benefits will have any long
lasting impact or will we go back to where we were as soon as the world starts up again?
Look, that's a really good question and it's unclear exactly how different countries will
progress, but this study has looked at that in terms of what the current reductions in
emissions might mean for the rest of 2020 and what they've estimated is that if the
restrictions continue throughout 2020, perhaps in a slightly reduced way, that there will
be reductions in the global emissions for the whole of 2020 by around about seven per
cent over the whole of 2020, whereas if for instance, the industrial activity and economic
activity is returning to a more normal level, we're likely to find that over 2020 as a whole
there would be about four per cent reduction in carbon dioxide emissions in the whole of
2020 relative to 2019. So uncertain estimates, but definitely a reduction in the whole-of-year
carbon dioxide emissions associated with human activity.
So that is a sliver of good news in what is a bleak time for pretty much everyone around
the world at the moment, but do you think that people can use this opportunity to transition
to a zero emissions economy?
What happens in the future really depends upon how countries use the economic stimulus
packages to get out of the current, depressed economic conditions. Some countries are arguing
and using the economic stimulus to transition their transport activities, their economic
activity, particularly in terms of transitioning to zero carbon energy sources for greater
use of renewable power, a greater use of active transport like bicycles and cycling or even
to transition to electric vehicles as long as the electricity they choose to charge the
electric vehicles comes from renewable or zero carbon energy sources. So there is an
opportunity to use this transition, these economic stimulus packages to rapidly transition
to a zero carbon economy around the world and that would then lead to massive long term
reductions in greenhouse gas emissions.
Is there anything else that you hope that people and policymakers can learn from this
pandemic with regards to climate change?
Look, there are a whole series of things that we can learn in the most important one in
my view is that although emissions fall at present, actually the carbon dioxide concentration
will continue to increase in 2020 because emissions are not falling to zero. What we
know in terms of meeting the commitments of the Paris agreement, which is seeking to limit
global warming to under two degrees above pre-industrial levels. What we need to do
is to reduce our emissions by three to seven per cent every year from now until 2030 and
beyond, if we're to have a good hope of limiting global warming to two degrees. And we also
know that even in 2020 with this essentially four to seven per cent emission reductions,
actually carbon dioxide concentrations will continue to increase. Global temperatures
will continue to increase and that's very likely to continue throughout the period from
now to 2030 and beyond, unless we rapidly transition to a zero carbon economy.
And is it too late to do so?
It is not too late to do so. We still have the opportunities of transitioning as quickly
as possible to a zero carbon economy. We may be too late to limit global warming to two
degrees, but everything that we do to limit greenhouse gas emissions will reduce the level
of global warming that will impact all people and all ecosystems and the environments all
around the world. We know that until we reach zero net emissions, global warming will continue
and that is going to happen until we go to net zero emissions.
Well it's good to know that there is still that we do have the tools and resources to
tackle climate change, but I think it's pretty obvious that it's going to take a global and
combined effort to do so. Thank you so much your insights and your time today Professor
David Karoly.
Your most welcome Michelle. And don't forget, for regular video updates
from the Australian Academy of Science, make sure to follow us on social media. I'm Michelle
Tapper, see you soon.