Why the sixth mass extinction is here. Now.

this video is about the new report from the intergovernmental panel on climate change but before telling you about that let me first tell you a brief story this video is also sponsored by brilliant more about them later in 1963 a zoologist named robert payne conducted an experiment in macor bay washington pain removed from the bay all individuals of a particular species of starfish known to predate on mussels in response as expected the muscle population of makobe exploded but something else interesting happened the ecological diversity of the bay collapsed of the 15 species present at the start of the experiment only eight remained at the end paine would go on to describe the starfish as a keystone species in macor bay a species that when removed caused the rest of the ecosystem to collapse scientists have subsequently identified many other keystone species such as gray wolves in yellowstone national park and the snowshoe hare in boreal forests science now understands that the biosphere including need i remind you humans is a vastly interconnected web that is very durable in some ways but in others is actually very fragile the removal of just a handful of species can cause the entire system to collapse so with all that in mind what does this document have to say this is the sixth assessment report from the intergovernmental panel on climate change's second working group so the first working group at the ipcc looks at the physical basis of climate change what's causing it and their latest report was released late last year this second group is concerned with the impacts of climate change how it's affecting humans and the world now and how it will likely affect us in the future what does this report say well to oversimplify it says that billions of people and a high proportion of all species on earth are being affected by climate change already those impacts include decreased food security more extreme weather events more widespread wildfires and changes in rainfall patterns all things that we have observed already the report also says that by continuing to emit carbon into the atmosphere today committing to further warming in the future those impacts will get worse and worse and in fact will quite quickly get so bad that we simply will not be able to adapt to them but to stress that earlier point it says that this isn't just a future problem climate change is already killing people destroying nature making the world poorer normally at this point in one of my videos i'd put in a joke or i put in a meme to try and lighten the mood about how like i don't know the report sounds like light reading but um this report is far too big and far too important to be fully covered in a youtube video like this so i'm going to link to some other youtube videos in a playlist up here on the screen and down in the description that i would encourage you to check out they're made by very talented people looking at different aspects of this report in this video i want to focus on just one aspect of this report to really drill into its significance i want to talk about the most existential threat described by the report the impact of climate change on the biosphere working group two's report summarizes the state of current research climate change has caused substantial damage and increasing irreversible losses in terrestrial freshwater and marine ecosystems the extent of climate change impacts are larger than previously estimated and some losses are already irreversible such as the first species extinctions driven by climate change while others are approaching irreversibility this is horrifying on its own but quite apart from the horror of watching climate change dismantle the natural world destroy the beauty the biodiversity there is a greater danger think back to the starfish in mako bay the report states that between three and fourteen percent of terrestrial species will likely face very high risk of extinction equivalent to being critically endangered today at one and a half degrees of warming at two degrees of warming that increases to between three and eighteen percent of species at three degrees between three and twenty nine percent of species the risk of a species going extinct in a biodiversity hotspot specifically such as a coral reef or the amazon rainforest is currently two percent a percentage that will double if the world warms by one and a half degrees and increase tenfold if the world warms by three degrees a scenario that is sadly entirely possible the risk is that we drive the starfish to extinction in makoor bay and the gray wolves to extinction in yellowstone and the snowshoe hair to extinction in canada and a whole host of species that we've not even had the time to yet identify as keystone species to extinction and cause a cascade of ecosystems to collapse one by one by one a mass extinction if that happens then we are not separate from the biosphere we are part of it in fact we are completely dependent upon it for for example our food production to quote the report climate change will increasingly put pressure on food production and access especially in vulnerable regions undermining food security and nutrition global warming will progressively weaken soil health and ecosystem services such as pollination increase pressure from pests and diseases and reduce marine animal biomass undermining food productivity in many regions on land and in the ocean put simply if we increase the risk of extinction across the board we increase the risk of keystone species going extinct making the collapse of ecosystems around the world more likely and if that happens if they go we cannot feed ourselves we go perhaps however this sounds like speculation to you like any prediction of the future it's difficult to take seriously unless there's data unless there are events in the past that mirror what we are predicting for the future unfortunately if we look at the fossil record at times in the earth's past when extreme climatic change happened that is exactly what we find i'm holly nanette i'm a phd student in paleobiology and i work on the responses of marine organisms to climate stresses in the past so there were five mass extinctions in the last 450 million years so the history of complex life on earth something gets classed as a mass extinction when the extinction rate is significantly above the background rate for example the permian triassic mass extinction the mother of all mass extinctions led to a loss of between 80 and 90 of species in the marine realm and between 75 and 80 percent of species on the land out of the five big mass extinctions we know definitely too that were rapid warming events they were caused by the emission of vast amounts of greenhouse gases into the atmosphere much like what we're seeing today only back before humans existed this emission of greenhouse gases came from gigantic volcanic provinces today it's us humans and we're also much quicker at it than the volcanic provinces were if you would like to learn more about paleoclimate that is climate in the past check out the mini series that i made with paulina and her colleagues linked in the description one of the things we discussed in that series was the response of different species to warming climates for ancient mass extinctions of course we don't have the option to study the changes within the organism's bodies but we can see larger scale patterns we see that species migrate pole words during warming events they shift the habitat away from the equator then secondly some organisms also show a decrease in the adult body size as a response to increasing temperatures we are seeing these responses today in fact they are some of the strongest bits of evidence we have that climate change is already affecting life on earth the working group 2 report notes that approximately half of all of the thousands of species studied showed climate-related changes in their territorial ranges moving pole words or to higher altitudes to try and stay cool enough what we are seeing today mirrors past mass extinctions because while certain organisms were able to adapt to changes in their climate in the past changes i should point out that were far more gradual than what we are seeing today adaptation was not the norm extinction was the historical record indicates that at our current unprecedented rate of warming humans are knowingly causing the sixth mass extinction in the history of earth a study last year estimated that a total global warming of 5.2 degrees celsius at a rate of more than 10 degrees in a million years would cause a mass extinction on par with the big five for context the current rate of warming that humans are causing as measured over the past century is approximately 17 000 degrees per million years if we get to a warming of 5.2 degrees celsius it will result in a mass extinction that is on the same scale as the ancient mass extinctions that is even without the other anthropogenic impacts like deforestation and ocean acidification the actual threshold is probably going to be lower how do you feel looking at stuff like the working group 2 report knowing what you do how does current changes make you feel afraid in talking about climate change it's important to toe the line between stressing the severity of the situation and stressing that the problem is solvable i hope that what you've just seen in this video has communicated to you the severity of this situation i know it can be difficult to believe given a background of wars and pandemics but this situation is truly dire we are looking at a human-caused mass extinction reaching that balance of severity and optimism is made especially difficult because this working group 2 report isn't about what we can do to mitigate and adapt to climate change that's in the next report from working group 3 due out sometime next month what working group 2 does stress is that we can do things and that while those things may vary in effectiveness across different regions the longer we leave it to take action the less effective those actions will be some of those actions are to directly prevent species from going extinct today something that charities such as dural have been doing for decades and now face unprecedented strain some actions are to protect the natural environment or to empower marginalized communities to protect their environment but most importantly demand the reduction of carbon emissions into the atmosphere the report next month will give details of how to most effectively do this but ultimately it's going to involve fundamentally rethinking how we think of energy use and energy generation the positive takeaway of this report is that it's not too late by taking action by demanding action and by listening to the working group 3 report that comes out next month we absolutely can still avoid this future of mass extinction and along the way we can make the world a more just place in a nutshell this report says that things are worse than we thought that the effects of climate change are here now and that they will get worse in the future the longer we delay meaningful action there's a very real risk of ecosystems starting to collapse around us soon but if we can limit future warming and if we can limit it to one and a half degrees celsius which is a really big ask but just about possible if we're super aggressive in cutting emissions then we can limit the damage and we can protect species all over the world there is a narrow window of time really this decade in which we can still stop this i wouldn't be able to spend as much time as i do on these videos and get these messages out to such a broad audience without the help of sponsors so please do stick around for just a moment to find out about brilliant who have kindly sponsored this video brilliant is an educational website and app that allows you to learn scientific and mathematical skills in a fun interactive way even if you're not in full-time education these skills are really valuable to learn the reports the ipcc put out for example are extremely condensed versions of thousands of scientific papers and that means they are very information dense so unless you have some amount of scientific or statistical literacy you are dependent on journalists and people like me to tell you what these reports say having an understanding of statistics for example unlocks a new powerful way of looking at the world and brilliant has a predefined learning path of expertly written courses on statistics featuring interactive problems that get you to apply your knowledge straight away rather than just reading and regurgitating information or if you prefer you could take their courses on computer science or logic or even relativity brilliant is also constantly expanding their catalogue of courses so whether you're a beginner an expert or anywhere in between there's an interactive lesson to help you improve and learn to get started for free and try out everything brilliant has to offer visit brilliant.org simon clark or click the link in the description the first 200 of you will also get 20 off brilliant annual premium subscription thanks so much to brilliant for supporting this video thank you so much for watching the video all the way through to the end if you've never shared one of my videos before then i would please implore you to share this one this is why i have this platform ultimately it's to try and communicate research and especially communicate research that has a positive impact that's this that's this video if you've never shared one before please now is the time thank you so much to paulina for speaking to me about her research again if you'd like to see the mini series that we did together i'll leave a link in the description and there's also a link to that playlist in the description of other videos made about the report and what it means by other talented youtubers please do check them both out if you would like to support dural and the work that they do preventing species from going extinct i'll also leave a link in the description to their website where there's lots more information about the work they do if you're staying on youtube here's some recommended viewing next if you enjoy the video please do pop a like and i'd like to again implore you to please share this one thank you again for watching and i'll see you in the next one

Channel: Simon Clark

Views: 78,446

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Id: MWVGCpNDroI

Length: 16min 5sec (965 seconds)

Published: Fri Mar 04 2022