A dire warning and a stark reality, global temperatures will rise.
It is unequivocal that human activity is driving this surge.
The extremes we're now experiencing, fires, floods, droughts and storms
will only intensify.
That is all part of a landmark report by a team of more than two hundred and thirty
scientists convened by the UN's Intergovernmental Panel on Climate Change.
The western U.S. is sifting through the ashes of yet another catastrophic fire
season, one that has only just begun.
And today, climate scientists at the United Nations made it clear
these extreme events are largely our doing.
This independent report released by the U.N.
is the starkest warning yet that the planet is warming to a dangerous degree.
It affirms that are burning of coal, oil and gas is accelerating climate change.
And the climate change is behind many of these extreme weather events.
The authors say these effects are happening far faster than predicted.
There's really one key message that emerges from this report.
We are out of time.
The 3000 page report is the work of more than 200 scientists from around the
world. They found that global temperatures are the hottest in 100000
years and many effects of climate change are already irreversible.
Those temperatures are on track to pass the targets set by the 2015 Paris Climate
Agreement and pass them decades earlier than expected.
The report says that if the planet warms beyond the target of one point five degrees
Celsius or two point seven degrees Fahrenheit, these extreme weather events
are forecast to be more frequent and more severe.
The report states that only by drastically cutting greenhouse gas emissions can
these extremes be lessened
Unless there are immediate, rapid and large scale reductions in greenhouse gas
emissions, limiting warming to one point five degrees C or
two point seven degrees Fahrenheit will be beyond reach.
Scientists say the consequences of climate change are ever present from the severity
of the wildfires and droughts in the western U.S.
to the devastating flooding across Europe just last month.
World leaders are set to assess today's report and plot their response
at the next global climate summit in Scotland this November.
For a closer look at today's report and the science behind it, we turn again to Michael
Oppenheimer. He's a professor of geosciences and international affairs at Princeton
University. And while he's not an author of this latest report, he is a long time
participant in the work of the Intergovernmental Panel on Climate Change.
Michael Oppenheimer. Always great to have you on the NewsHour.
The head of the UN referred to this as code red for humanity.
Do you share that, that dire assessment?
Unfortunately, I do.
The forecast is really grim.
The climate is changing at an accelerating pace, and that means basically we're in
trouble. More intense heat waves, heavier precipitation during extreme rainstorms,
droughts, hurricanes shifting to more Category four and five.
The longer we wait to reduce the emissions of the greenhouse gases like carbon dioxide
that are causing the problem, the worse it's going to get.
One thing that really jumped out at me in this report is the attribution science directly
connecting climate change to specific events
that seems to be getting particularly sharp.
Are we getting better and better at making those linkages
so much better? I mean, even 15, 20 years ago,
we really couldn't make specific statements about specific events and we would
declare that is the case.
We would make general statements about what's the global trend, for
instance, now, rather than in these general statements about the havoc
that climate change is causing. We can make very specific statements about what has
happened, in particular events at particular places.
At particular times we can say how much climate change increase
the chances of an individual damaging or deadly event having occurred
in the first place. That would be, for instance, the intense rainfall that occurred in
2017. And Hurricane Harvey, that was about 50 percent or more
what it usually would be without the greenhouse gases in the atmosphere.
It would be like the cause of the Australian fires where we could say
wildfires two years ago, where we could say specifically
what's the percent that climate change increase the likelihood
of that event happening or it'll be done, I'm sure, shortly for the
tremendous heat event that occurred in the Pacific Northwest a few weeks
ago that was so off the charts.
I think it's going to be relatively easy to say climate change was responsible
for a big share of it. We'll see exactly what the data shows as the analysis
is done. So that makes climate change real for the average person.
And it's no longer a matter of speculation as to whether a bad event
that we suffered through was caused by climate change.
We can say with some precision exactly how much climate change is responsible.
That's called attribution.
This report also points out that we have increasingly little time to
act. Can you talk a little bit about the urgency that the UN is putting forward
here? Is there a window of time for action that is closing?
Well, the general message is without large and rapid reductions in emissions
of the greenhouse gases will rush into what I call a climate danger
zone, that the warming of greater than
about three or four degrees Fahrenheit, one and a half to two
degrees Celsius that the countries agreed to avoid in
the 200 in the 2015 Paris Agreement.
In that zone of danger, impacts continue to accelerate, compounding
and concatenating beyond society's ability to successfully
adapt. That's why countries said we shouldn't go there.
On the other hand, if we get serious about rapid,
immediate reductions and large reductions in the emissions of these gases,
we could produce a notable slowing of the warming within 20 years.
Now, I don't know, and I don't think anybody could say with any sureness whether we're
going to make the one and a half or two degree limit stay out of the danger zone.
But even if we get into the danger zone, the quicker we get out of it, the better.
So this is not and in the end, this is not a problem.
That's a technological or scientific one.
It's a political one.
Basically, you pointed out that cutting greenhouse gas emissions
is the key here. And we have seen a lot of nations make big pledges,
less so big action.
President Biden, we have seen right now is had to trim his very ambitious
climate goals in the negotiations in the Congress and the Senate.
Do you have any confidence that the United States, let alone all these other nations,
will actually act in time?
Well, let's talk about some good news first.
There's kind of a wind at the back of the countries that do want to act because we're
in the middle of an energy revolution.
We're talking about electrifying the whole system, including the transportation.
Eventually that electricity can be produced by carbon free energy and
that will help get us out of the problem.
And all of it is it looks like it can be done at a reasonable cost because cost
of renewable energy are plummeting.
Now, as I mentioned a second ago, is the political will really going to be there
to do that? It's very complicated.
You have to make interest groups in a bunch of countries that are the big emitters happy
with a serious program to cut emissions.
I'm not a politician. I can't say whether it will be done.
I can say that these countries have moved mountains
were moved heaven and earth before on big problems, usually national security.
This is as big as those problems.
They've got to do the same thing again, whether they will or not.
Well, it's partly up to us to try to put the pressure on our governments to make them do
it.
All right. Michael Oppenheimer of Princeton University, thanks for joining us on this
very sobering day. Always good to see you.
Thanks for having me.