It's clear that rising levels of greenhouse gas emissions are warming the planet and triggering
profound environmental changes. What is less understood is exactly how the climate systems
that govern our weather are being disrupted and how much worse things will get in the
years and decades to come. For some answers, I reached out to a climate expert Dr. Jennifer
Francis of the Woodwell Climate Research Center. (Bryce) Thank you for joining me,
welcome. (Dr. Francis) Pleasure. (Bryce) Woodwell was named the top climate change think tank in the
world for four straight years from 2013 to 2016. This first part of our conversation - linked
below - is a brief crash course on how we've reached one degree of warming so quickly.
(Dr. Francis) 20,000 ago was the last ice age that the earth experienced and that's on the
left hand side of that graph. We've basically been warming up -the big ice sheet over North America
retreated - and pretty much since 8,000 years ago or so we've been living in a fairly constant
global temperature with a slight cooling starting to happen. And that whole piece of the temperature
record is all controlled by natural processes: things like changes in the tilt of the earth's
axis relative to our orbit around the sun, changes in the earth's orbit around the sun,
things like that. So of course we weren't around before several thousand years ago,
but all of those changes that we observe back in time there are just caused by natural effects. But
of course what's happening just in the last century or so is this huge digression from
what would have been a continued cooling trend, and instead we see this huge spike in warming.
(Bryce) The evidence is in the ice cores. By extracting and analyzing a
column of ice that hasn't been exposed to air since it was frozen, the exact makeup
of the atmosphere back then is revealed. (Mark Twickler) "The unique things about
polar glaciers is each year that it snows there the snow never melts so you get one year of snow
on top of the next year of snow--it compresses. So everything that fell out of the atmosphere:
dust, salt from the ocean, volcanic ash, is preserved in that ice core.
(Bryce) Sure enough, these ice cores show that greenhouse gas concentrations fluctuated within
a tight range until innovation allowed us to use an increasing amount of coal
oil and methane gas. This terrifying visualization shows how fast observable temperatures have risen
since we began deviating from the stable, natural cycle revealed in the ice cores.
(Dr. Francis) As human activity has increased so have the types of greenhouse gases we emit
and how we emit them. (Dr. Francis) We know with
100% confidence that this is being caused by human factors which include - not just the
burning of fossil fuels and contributing greenhouse gases to the atmosphere, which
of course trap the heat - but also things like deforestation and changes to the land surface.
(Bryce) The effort to prevent catastrophic warming culminated in 2015 in Paris when the world set the
long-term goal of limiting the increase in the average global temperature to well below
2 degrees Celsius by the end of the century. (Dr. Francis) The Paris Accord, the design of
that, is to try to keep the globe under 1.5 degrees Celsius warming if possible
and certainly below 2 degrees Celsius. Because we believe that beyond 2 degrees is really
catastrophic in many ways. (Bryce) But the Paris agreement
left each country to set up their own emission targets and report their own progress. On top
of that, there isn't even a mechanism to force countries to hit these targets
by any specific date. Although president trump has withdrawn the United States from the agreement,
President-elect Biden has pledged that the United States will re-enter it the first day he takes
office in January. It is unclear though if Biden will be able to strengthen the agreement further,
although it is clear that the world quickly needs to. (Dr. Francis) Some areas of the
United States have already warmed beyond that limit that we're trying to keep the globe to.
(Bryce) Well beyond. (Dr. Francis) Well beyond, exactly. And
if you were to look at a graph like this for the arctic you'd see almost the entire arctic has
totally blown by the two-degree mark. So the story here is that you know we're on a trajectory right
now that is not very good--it's pretty pessimistic in terms of trying to keep to the Paris Accord
unless we take very strong action very soon. (Bryce) The full version of my conversation
with Dr. Francis is available to members of my new website, TDC.video
Membership also makes a great gift for anyone in your life concerned about climate change.
But however you watch TDC, thanks! Until next time, I'm Bryce Plank.