The planet's coral reefs have crossed a point of no return. When oceans get too warm, corals bleach and die, a disaster for marine life. “When you lean back on a chair, there's a point where a small nudge can create a very different stable state. That's what's happening to the coral reefs." WATCH Coral reefs cross survival limit, in Earth's first catastrophic climate tipping point- FRANCE 24 Oct 14 report, transcript follows:
We've been experiencing unusual warmth at a planetary scale, but also heat waves in the ocean. Global warming is passing dangerous thresholds sooner than expected and the world's coral reefs are now in an “almost irreversible state of decline.”TRANSCRIPT: This is Apropo. The planet's tropical
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coral reefs have almost certainly
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crossed a point of no return. That's
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according to a major new report from
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scientists and conservationists who are
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warning that global warming is passing
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dangerous thresholds sooner than
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expected and that the world's coral
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reefs are now in an almost irreversible
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state of decline.
[Transcripts are at Heating Planet for readers writers and researchers. Plus video can disappear. The printed word is forever.]
Yinka Oat has the
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details.
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Oasis of life and color right in the
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middle of the ocean. Coral reefs are a
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haven for marine life and divers alike.
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But this underwater paradise is fragile
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and under threat from climate change.
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When the water gets too warm, corals
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bleach and die.
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Now, a new study released on Monday
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warns that humans have already caused so
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much global warming, the damage to reefs
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may go beyond repair, suggesting we may
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have passed a tipping point, a disaster
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for marine life.
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There are countless species of corals
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with different shapes, and all these
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shapes create ecological niches where
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certain fish species can hide from
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predators or find a place to live.
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This rich underwater world supports
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incredible biod diversity. Up to 30% of
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all known marine species rely on coral
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reefs at some point in their life cycle,
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especially fish.
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Millions of people who rely on fishing
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could lose their livelihoods,
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particularly in Southeast Asia, where
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coral reefs are widespread. But they
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offer more than just food. They also
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break waves, helping to reduce storm
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damage. Without them, many coastal areas
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face erosion and flooding. Today, 500
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million people depend on coral reefs for
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food and protection from the ocean.
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For more, let's bring in the lead author
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of this report, Tim Lantern, who is also
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the founding director of the Global
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Systems Institute. Great to have you
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with us on the program this evening,
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Tim. So, the Earth has reached its first
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catastrophic climate tipping point. What
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exactly does that mean? And talk us
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through how exactly you and your fellow
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researchers came to this conclusion.
2:23
Well, as that lovely report showed, it
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means that change in this case in this
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incredible ecosystem is now happening in
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a self-propelling way um in a bad
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direction. And that's the nature of
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tipping point change. Um, if you was
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want to think about a familiar example,
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when you lean back on a chair, you know
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that there's a balance point where a
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small nudge can create a self-propelling
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change of you and the chair into a very
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different stable state. That's suddenly
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what's happening to the coral reefs and
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it's what's happening or what's at risk
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of happening for many other um critical
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parts of our life support system. The
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way we could tell um that this was the
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case for coral reefs is just in the last
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couple of years, we've been experiencing
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unusual warmth at a planetary scale, but
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also heat waves in the ocean in the
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tropics that have taken they've taken
3:19
the global temperature above 1 and a
3:22
half° centigrade above the
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pre-industrial level where we'd already
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estimated the corals would pass their
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tipping point. And sure enough um over
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80% of them have been experiencing these
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extreme bleaching events and dieback
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rather confirming the prediction. And at
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the same time it's become clear that the
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world is going to carry on warming and
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what has been a temporary experience of
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1 and a half degrees of warming is I'm
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afraid going to become um that's going
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to be the average temperature within a
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few years probably and we're going to
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carry on above that. So that's why we
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can say the reefs are now in risk of
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large scale irreversible decline. It's
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not a case of all hope is lost, but it
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does mean we need to focus on those
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crucial reef ecosystems on the the
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cooler end of the range that we can
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still perhaps preserve or protect and
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reduce the other pressure on those reefs
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like over fishing and pollution um to
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give them some resilience. And then in
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the big picture, we've got to cool
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eventually the climate back down again
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if we want this incredible ecosystem to
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be the flourishing familiar thing it's
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always been.
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So not to give up hope entirely is what
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you're saying though. Is it is it
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inevitable though, do you think
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realistically speaking that perhaps not
4:41
within the next few years, but they will
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eventually perish these coral reefs or
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can something realistically be done to
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to reverse this damage and to restore
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them?
4:53
Well, I fear that many of them are at
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risk of of of being lost, but a fraction
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could still be preserved, and we should
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we should work to preserve that
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fraction. And many coral reef
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conservationists are already trying to
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do that. So, as I've emphasized, it's
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kind of crucial to reduce all of the
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different human drivers on the reefs to
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give them the ones that have a chance of
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survival the best chance, the most
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resilience. But there's innovations
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going on. People are experimenting with
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trying to breed um strains of coral that
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are more tolerant of the warm conditions
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over the Great Barrier Reef. There's
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even efforts to um seed the air with uh
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sea salt that will make the clouds
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brighter that will create a kind of um
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sun shade or better cooling effect over
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the reefs. I think we have to think in
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those terms of what can we best do to
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support uh the resilience of some reefs
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to give a chance that in the future we
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if we eventually cool the climate back
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down again they have a chance to should
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we say recolonize.
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But then the crucial message there is to
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we have to limit uh we have to stop
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global warming first and then and then
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begin to reverse it. And that's why our
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report also emphasizes the potential to
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trigger what we call positive tipping
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points where we can accelerate the
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change we need to to zero emissions
6:18
technologies and behaviors.
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And just tell us why are coral reefs
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themselves so vulnerable and what kind
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of impact does it have when they're
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starting to perish on the wider
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ecosystem also on the people who live
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close to coasts right around the world
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particularly in these more tropical
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these warmer regions.
6:39
Yeah. So, one reason you you could that
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that they're vulnerable is a coral reef
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is um already an amazing partnership or
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symbiosis we call it between the coral
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which is actually an animal and some
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photosynthesizing algae that kind of
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live in partnership with it. But that
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seems to be quite a sensitive
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relationship. So when it gets too hot
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the the corals will reject their algal
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partners in the bigger level of the
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ecosystem. Coral reefs are actually
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living in kind of nutrient deserts in
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the ocean. And that and yet, as we can
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all see from the pictures, they're this
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abundance of life. And the only way they
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can support that flourishing in
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abundance is because they're brilliant
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at cycling all the nutrients and
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resources they need within the system.
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And it's not just the corals and the
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algae that play a part in that. It's the
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sponges. It's the reef fish. It's all
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the amazing panop that we see as
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colorful life. But but when you start to
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break down those recycling loops, uh you
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switch the system can switch into
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another state where these bleached out
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corals that have rejected their algae,
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these tiny algae that their partners.
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Unfortunately, instead the system gets
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colonized by bigger algae, seaweed we'd
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think of it, that can cloak the coral um
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make a much less diverse system that and
7:59
and that makes it hard or or very
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difficult for the for the original coral
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ecosystem and all those partnerships to
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to recolonize. So that's that's a little
8:10
bit about, you know, why you have a
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system which uh is vulnerable when its
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natural cycles get broken down. Um yeah,
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in terms of the the bigger picture of
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why is this so important? Well, it it's
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all of that amazing cycling of resources
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that makes them so so abundant with
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life, including fish and that provide um
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abundant fisheries for many many people.
8:35
And as the opening report showed, at the
8:38
same time, the coral is this kind of
8:40
self-regulating system that is this that
8:43
has grown up if the sea levels have
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risen over over thousands of years since
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the last ice age and presents this
8:50
natural barrier to the incoming tide in
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the waves. But unfortunately when you
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lose a reef and the system starts to
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degrade that can can literally break up
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and we'll lose or the communities behind
9:02
those reefs will lose their shoreline
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protection. So these things add up in
9:08
terms of the what we call ecosystem
9:10
services they provide. And then recent
9:13
recent EP estimates will say that the
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total value of all of this this the
9:19
human value of eco of these ecosystems
9:22
could be of the order of $2 trillion per
9:25
year which is phen phenomenal. So
9:28
there's a lot at stake in a you could
9:29
say in an economic sense as well as in a
9:32
ecological sense. And Tim, your your
9:35
report also, you know, refers to this
9:36
being the first catastrophic climate
9:38
tipping point. You are concerned that
9:40
others are approaching the report also
9:42
coming just ahead of the COP 30 climate
9:45
change conference which is going to be
9:46
taking place in Brazil. The Amazon being
9:49
a real concern as well, isn't it?
9:52
It is because just in the last couple of
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years, new research has shown that the
9:57
Amazon that we knew was at possible risk
10:00
of of its own dieback. Um is now at
10:04
greater risk than we thought because of
10:06
the combined effects of not just climate
10:08
change, which uh is causing some
10:12
extraordinary droughts and fires that
10:14
start to destroy parts of the forest,
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but also people are still directly
10:19
chopping it down. And unfortunately in
10:21
the last year or so deforestation rates
10:23
have shot up again. And together that
10:26
direct human pressure and then the wider
10:28
pressure of climate change means that
10:30
the Amazon could be at risk of a tipping
10:31
point below 2° centigrade of global
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warming. And so we'll be getting into
10:36
the danger zone of 1 and a half to two
10:38
degrees centigrade of global warming.
10:40
Probably unfortunately entering the
10:42
danger zone after 2030. And that's kind
10:45
of iconic when the COP 30 meeting is
10:47
happening in the Amazon. And of course,
10:49
the Brazilian presidency is very aware
10:53
of that and and also very committed to
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wanting to to to create to mobilize
11:00
global action to to try and protect this
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critical ecosystem. Both ways, they've
11:05
got to reduce the illegal largely
11:07
illegal um destruction of the forest,
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but they need all of us um getting on
11:12
board with accelerated climate action to
11:14
to limit global warming. Tim Lon, lead
11:17
author of that global tipping points
11:18
report.
***
France 24 Oct 14
***
[KE: Everything climate scientists predicted about global warming since the 1970s is coming true only faster, but coral reef bleaching is happening way faster than predicted, which is ALARMING]
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