Europe's top climate agency released# data today showing global temperatures## averaged 1.48 degrees Celsius or 2.66# degrees Fahrenheit above preindustrial## levels.

Record high temperatures# are expected to continue this year.

For more on the implications of this record heat,## I'm joined by Radley Horton.

He's professor# Radley, welcome back.

So, the planet did shattered previous records.

Did we expect# to see that kind of increase this quickly?

RADLEY HORTON, Columbia University# Climate School: No, we did not.

At this point, gotten used to hearing this is the ninth# straight, the nine last years have been the## nine warmest on record.

But what we had happen# this year is that, over the last six months,## we were half-a-degree Fahrenheit height# warmer than any of those previous years.

So you could think of it like all the# previous years were stacked pretty close## together.

And along comes a year in# 2023 where the last six months were a## full half-a-degree warmer than any of those# previous years.

So this was not expected.

AMNA NAWAZ: So how do we account for that?# What drove that increase this past year?

RADLEY HORTON: Yes, well, we have# to start -- there's a few factors,## but we have to start with human# activities, the We're putting so much more heat in the system,# and there's growing concern among scientists## that we may have underestimated# just how sensitive the climate,## the Earth's temperature is to greenhouse gases as# they increase.

Are models missing some p But there are some other things going on# besides that -- those human activities.## We had a very -- a moderately strong# El Nino that's under way right now.## That can be responsible for some warming of the# planet, but not this much.

And then, simi we had a volcanic eruption under the ocean that# actually put water vapor up into the atmosphere,## which, unlike most volcanoes, is effective# to some degree at warming the planet, but,## again, couldn't anywhere come close to explaining# this degree of shattering of previous records.

AMNA NAWAZ: So we know global# warming doesn't just mean more## heat and hotter records.

We know it also# means more ext have we been seeing those?

Where is it# becoming real for these communities?

RADLEY HORTON: Yes, and there's so many examples.

I will highlight some of the ju st as the global average temperatures# did.

You look at the degree of so these heavy rain events, these tragic# floods in 2023, like we saw in Libya,## for example, in Greece, certainly# heat waves front and center, right?

We saw exceptional heat across# Southern Europe, across China,## across the Southern U.S.

So this is# hugely impactful for our economies,## for our ecosystems.

How about the forest fires# that we saw across Canada?

By some estimates,## four times more burned area than ever before# seen in Canada.

It's directly related to the## planet warming, more than we thought it could,# causing the air to dry out and essentially suck## moisture out of that vegetation, priming# the pump for these really extreme fires.

AMNA NAWAZ: And we should underscore,## we're ta I want to point out the U.S. alone had 28# weather disasters last year.

The combined damage killed 492 people and caused# nearly $93 billion in damage.

In short,## can we afford to continue at this pace?

RADLEY HORTON: Well, no, we can't.

We have to urgently reduce our We can see it by looking at the damages# this past year, economic and loss of life## and some of those things that don't# get captured by metrics like GDP.

But the additional concern, as you note,# because this year was so much warmer t prior years and because of growing evidence# that we may have underestimated how vulnerable## we as a society are to a little bit higher# temperatures, it's becoming clear that,## if we want to avert these worst-case scenarios# and possible really catastrophic outcomes that are## beyond what our climate models or our financial# models or our crop models tell us is possible, we## need to urgently reduce emissions and we have to# adapt to these climate changes that are under way.

AMNA NAWAZ: Radley, that 1.48 degree# increase is just barely below the## 1.5 degrees limit that the world agreed# upon as what they would like to avoid to,## as you mentioned, avoid those worst-case# scenarios and the most severe outcomes.

We talk about the tipping point a lot.

Is this it?

RADLEY HORTON: Well, I'd say we don't# need to focus exactly on Really, the key takeaway, I think, is that we# are failing terribly at reducing our emissions.## But you're right that it's becoming# more and more clear than it was just,## say, five years or so ago that getting to# 1.5 degrees is catastrophic for We have underestimated how vulnerable# our systems are.

We have underestimated## how quickly these extreme events like heat# waves and heavy rain are going to change.

So, in that sense, whether it's a tipping point or# not, we're way more vulnerable than w and it's even more urgent than we thought# that we dramatically reduce our emissions.

AMNA NAWAZ: Radley Horton, professor at# Columbia University's Climate School,## thank you so much for joining us.

RADLEY HORTON: Thank you.