SciCafe: The Sixth Extinction - Biodiversity Under Threat

The Sixth Extinction: Biodiversity Under Threat

Published December 28, 2017

[The Museum’s logo appears over a man in front of a podium.]

[Joel Cracraft, Curator in the Division of Vertebrate Zoology speaks to an audience.]

JOEL CRACRAFT (Curator, Division of Vertebrate Zoology): I want to talk about biodiversity and the sixth extinction.  And there’s a lot of controversy over that. There are a few people in the world that don’t think we’re under an extinction event, and I want to tell you otherwise. But I want to give you a more holistic view of this event.

[On-screen text appears over white: “What is biodiversity? Species diversity, genetic diversity, ecological diversity”]

CRACRAFT: Now I just want to give you a few reminders of what biodiversity is. So we look at it as species diversity, we look at it as genetic diversity of all those species, and we look at it as ecological diversity. And right now, there’s maybe 1.4, 1.7 million species discovered and described, but we scientists debate how many are actually on Earth. A lot of entomologists, there’s kind of a median idea that there’s maybe 10 million. Many of us who think a lot of biodiversity is very narrowly distributed, and that many of these invertebrate groups are much more speciose, some of us think that may be even as much as 20 million.

[On-screen text appears over white: “Why is biological diversity important? Ecological Services (Clean water and air, climate, biogeochemical flows (CO2), soils). Economic Use (Shelter, food, fiber). Promoting the human spirit and intellect (Recreation, arts and sciences, etc.).]

CRACRAFT: In any case, biodiversity is really, really important for us. If you like breathing clean air, drinking clean water, having your ecosystems filter out the water, if you’re interested in having carbon in the atmosphere sequestered in forests, then ecological services are really, really important.

And then, just thinking about all we eat, our homes, food and fiber, very, very important. But also I think really important is the idea that biodiversity, ecosystems, natural wildlands, promote the spirit and human intellect, and have always done that.

[Images appear of rhinoceros, thylacine, fish, pangolin, passenger pigeon, quagga, and other endangered or extinct animals.]

CRACRAFT: Now we’re going to talk a little bit about the transformation of the biosphere. All these kind of cute cuddly-wuddlies are all extinct or almost extinct, and the debate is whether we’re in the middle of a sixth extinction.

[Cracraft stands in front of podium, speaking to audience.]

CRACRAFT: And that’s a very complicated topic that I don’t have time to go into, but I think that probably thousands of species have already gone extinct. And the reason why I kind of think that is we sort of know that as the Polynesians spread across the Pacific, they pretty much ate everything on all those specific islands. And there’s a fossil record, for birds, anyway, of lots of species that are no longer there and haven’t been there for a very, very long time.

But the wildlands are being converted at a tremendous rate, and we’ll talk about that. And we’ll talk about biodiversity is massively disappearing on the face of the Earth. And it’s populations and species; those are the currency that we’ll be talking about. So let’s look at some of this evidence.

[On-screen text appears over white: Extinction: The last individual organism of a species dies. Extirpation: The last individual organism of a species within one population dies. Extirpation of all populations = Extinction. Habitat Fragmentation: Large habitats are divided into smaller, more isolated habitats.]

CRACRAFT: Extinction is about the last individual organism of a species dying. So when a population is extirpated, that’s the last individual of that population. When the last population and the last individual of the last population is gone, then that’s extinction. So mechanistically, it’s all about fragmentation. 

[Cracraft stands in front of podium, speaking to audience.]

CRACRAFT: Now fragmentation is important because as populations get more and more constrained and smaller, then the probabilities of them going extinct stochastically, by chance, go way, way up. And we know that’s a very important thing.

[On-screen text appears: Fragmentation. Under the text, are photos of Rio de Janeiro’s cityscape with the word “Urbanization”, a paved road running between houses with the word “Roads”, tree trunks scattered across a landscape with forest in the background and the word “Deforestation”, and an aerial view of agricultural fields and the word “Agriculture.”]

CRACRAFT: These are four examples of major mechanisms of fragmentation in the world. So Rio and urbanization has fractured the rain forest all around Rio. Roads are really, really important. Within the next 20 years they are going to build more roads that can go around the globe six times.

[Cracraft stands in front of podium, speaking to audience.]

CRACRAFT: Right now, there’s over 190,000 kilometers of undocumented roads in Amazonia. So roads are everywhere. Everybody builds roads. And it’s one of the major components of driving fragmentation.

Deforestation drives it. So does agriculture, has driven it. So fragmentation is a really important mechanism by which we lose individual organisms. They’re fractured into small populations and then they go extinct. 

[Graph titled “Vertebrate Population Abundance.” Y-axis is labeled “Index Value (1970 = 1)” and ranges from 0 to 2. X-axis is labeled with years from 1970 to 2010. Citation reads: From “Living Planet Report, 2016.” By World Wildlife Fund and Zoological Society of London. 2016.]

CRACRAFT: And this curve is the vertebrates that are being lost globally. Now this is a really interesting study because it’s based on real world data on the ground:

[Text appears next to the graph: 14,152 populations monitored. 3,706 vertebrate species.] 

CRACRAFT: 14,000 populations monitored, 3,700 species of vertebrates around the world.

[Arrow points to index value of 1 on y-axis. Text appears: 1 = Population abundances in 1970.]

CRACRAFT: These are long term ecological studies, and this study started here in 1970. So we set that at one.

[On-screen text appears on the slide: 58% overall decline since 1970.]

CRACRAFT: And right now, across all those populations, on average there’s been a 58 percent decline in the number of individuals in those populations. That’s massive. That’s massive. And these are vertebrates. 

[A new slide appears. On-screen text reads: Primates in Peril – Population Decline. 60% of the 504 species of primates are threatened. Madagascar – 87% of primates threatened. Asia – 73% of primates threatened. Americas – 36% of primates threatened. Africa 37% of primates threatened.]

CRACRAFT: So primates in peril, I’ll give you this picture. Populations declining; 60 percent of the 504 species in the world of primates are threatened, which means that their populations are declining. Madagascar, it’s as much as 87 percent; Asia, 73; America, 36; Africa, 37. So these close relatives of us are disappearing in many, many places.

[Cracraft stands in front of podium, speaking to audience.]

CRACRAFT: Now if you think this is depressing, then you will be even more depressed after I tell you about this next slide. These are insects. And I know most of you don’t like insects. You just don’t like them.

[New slide appears, titled “Insect Loss In Germany.” A graph on the left charts the decline of daily biomass from 1990 to 2015. A graph on the right compares the grams of insects collected from May through October in 1989 to those collected in the same months in 2013. The 2013 numbers are much diminished. Citation reads: From “More Than 75 Percent Decline Over 27 Years In Total Flying Insect Biomass In Protected Areas.” By Hallmann, et al. PLoS ONE 12 (1): E0185809.2017.]

CRACRAFT: But this is a very recent study showing that in 63 protected areas, protected areas in Germany,  there’s been this 75 percent decline in 27 years—only 27 years—of biomass of flying insects.

[Cracraft stands in front of podium, speaking to audience.]

CRACRAFT: Now insects are really important, because they pollinate everything. Agriculture would not be really easily possible without insects. In the United States, the ecosystem services from insects is $57 billion alone. Insects are the food chain. So insects go, birds go. 

I was astonished when this study just came out. It was astonishing. But this shows you that it’s things other than these, like the cute little critters and stuff, that are disappearing. Everything is disappearing, really. 

[Slide of map titled “Predicted Local Loss of Species Richness by 2090.” Map of the world charts predicted species loss from “Gain” to more than 30%. Some regions in the northern hemisphere are generally gaining, but there are areas of heavy predicted loss in the central United States, Brazil, sub-Saharan Africa, Asia, and Australia. Citation: From “Living Planet Report, 2016.” By World Wildlife Fund and Zoological Society of London. 2016.]

CRACRAFT: Now this is a model, and this model is based on the land use and predicted future land use, expected effects due to climate change.

[On-screen text appears below map: In ~70 years, much of the globe will lose more than 30% of its species.]

CRACRAFT: And what it’s showing is that in 70 years, much of the globe will lose more than 30 percent of its species. So they’re trying to model what will go extinct in about 70 years. They’re saying 30 percent, and if it’s dark red, that’s more than 30 percent of the species go. And then all the way down. 

And up north there’s going to be a gain because climate is moving, and I’ll show you what’s going to happen to the United States by the end of the century, and it’s not pretty. And it shows this kind of a thing, everything moving north.

[Cracraft stands in front of podium, speaking to audience.]

CRACRAFT: So clearly, we’ve got a major problem in River City, folks. 

Now, I want to talk about three primary causes. The first one is going to be population, the second one is going to be consumption, and the third is going to be climate change, and how all three of those fit in to the loss of biodiversity in ecosystem services. 

[Slide with graph titled “Population Growth”. Y-axis is labeled “Population (Billion)” and ranges from 0 to 14 billion. X-axis is labeled with years from 1950 to 2100. Graph to 2015 shows estimated population. From that point forwards, a dotted line representing medium population size grows from about 7.5 billion in 2015 to about 10 billion in 2100. Prediction intervals are represented by a shading above and below the dotted line. Citation: From: “World Population Prospects: The 2017 Revision, Key Findings and Advance Tables.” By the United Nations, Department of Economic and Social Affairs, Population Division. Working Paper No. ESA/P/WP/248. 2017.]

CRACRAFT: The first one, of course, is population.

[Arrow points to beginning of dotted line in 2015. Text next to the arrow reads: ~7.5 billion now.]

CRACRAFT: We know we have around 7.5 billion people on Earth right now.

[Arrow points to dotted line at about 2050. Text next to the arrow reads: Conservatively, 9.5 billion in 2050.]

CRACRAFT: It’s projected that by 2050 we’re going to be probably in the neighborhood of nine and half, and by the end of the century, well, the expectations curve out, and under a median expectation…

[Arrow points to end of dotted line in 2100. Text next to the arrow reads: ~11/12 billion in 2100.]

[Arrow points to upper edge of predicted population range in 2100. Text next to the arrow reads: Up to 16 billion.]

CRACRAFT: …well, we might have in the neighborhood of 11, 12 billion people, up to maybe 16 billion, by then, depending on the assumptions that go into all these models. There are always going to be assumptions.

[Cracraft stands in front of podium, speaking to audience.]

CRACRAFT: Now, the second is unbridled consumption by, I need, I want, I need, I need, I need, I want. And when I say “I”, I mean me, you, we, business entities, political entities, nation states, whatever. Everybody wants and needs something. And there are lots and lots of people out there trying to convince us to want more, from all levels of government all the way else, because now growth is the global philosophy. Growth will get us out of our problems.  It will solve all the problems if we just grow, grow, grow. 

But all this want, all this need, has to come from someplace, and that is from Mother Earth itself, and from biodiversity on Earth. And it increases our ecological footprint, and I’m going to talk about that in a little while. But this is it, man. This is the only place we have to get stuff, and we are getting stuff at a rapid rate and have been doing this for quite a long time.

[Slide with photos of four agricultural scenes—hay rolls, plowed furrows near a lake, rows of green crops, and stalks of grain.]

CRACRAFT: Now, we’ve converted almost 40 percent or more of the land of the world to agriculture. We have to feed people, and so we’ve increased it.

[Cracraft stands in front of podium, speaking to audience.]

CRACRAFT: And we’re doing all kinds of really cool things to increase productivity for food to feed the hungry parts of the world, and to keep feeding us. And we throw fertilizers and we irrigate more and more crops.  

We’ve cut virtually all the original forests out of where people mostly live.

[Map of the world titled “Global Forest Loss.” Areas in Canada, Alaska, the northern part of Amazonia, some parts of central Africa, and northern areas of Europe and Asia are shaded green. Areas in Canada, the southern United States, Brazil, sub-Saharan Africa, Europe, and Asia are shaded pink. Citation: Global Forest Watch. 2017.]

CRACRAFT: You can see in green, that’s still original forest, and in red is all the forest that’s been cut, and it’s an awful lot of forest. We’ve made major impacts on the marine realm.

[Map of the world titled “Marine Exploitation.” Coastal areas around northern Europe, East Asia, and some parts of North America are shaded red to reflect Very High Impact. Equatorial areas are generally shaded orange to reflect Medium to High Impact. Waters around Antarctica and above northern Asia are blue to reflect Very Low Impact. Citation: From “A Global Map of Human Impact on Marine Ecosystems” by Halpern, et al. Science. 15 Feb 2008: 948-952. Reprinted with permission from AAAS.]

CRACRAFT: So this heat map with things that are red and orange and yellow, that shows heavy, heavy exploitation, and the less exploitation is in blue. But we’ve clear cut, basically, mostly the fisheries. 

[Cracraft stands in front of podium, speaking to audience.]

CRACRAFT: Now we’ve leveled off in actual fisheries because now aquaculture, with its own problems, is taking over. But so many people in the world depend on marine organisms for protein; huge, huge numbers of people. But we’re overfishing, and pollution is major, especially around the coastlines. 

[Slide with graph titled, “Waste Generation and Income.” Y-axis is labeled “Waste Generation Per Capita (KG/YR) and ranges from 0 to 1,000. X-axis is labeled “Gross National Income Per Capita (USD) and ranges from 200 to 100,000. It is subdivided into sections labeled, “Low, Lower-middle, Upper-middle, and High.” Dots representing many Western countries, including Canada, the United States, Switzerland, and Denmark are clustered at the right of the graph, reflecting a high gross national income and a great amount of waste generation. Countries on the far left—low income, and low waste generation per capita—include Burundi and Benin. Citation: From “Global Waste Management Outlook.” By the United Nations Environmental Program, 2015.]

CRACRAFT: Now we create so much crap that we just throw it away. So you can see that over here, Canada, U.S., Switzerland, Denmark, Ireland, per capita and kilograms. For instance, the United States, every person in the United States gets rid of around 750 kilograms a year, and then it goes down into upper middle income countries down to low countries. But the thing here is, everything is growing.

[Cracraft stands in front of podium, speaking to audience.]

CRACRAFT: More and more and more waste is growing. 

Because when you think about it, we’re organisms. We take food and matter in, and we shove out waste and dissipate energy. And so we have billions of organisms, human organisms, doing this. We consume a lot and we get rid of a lot. 

Now our ecological footprint of humans is totally out of control. What do we mean by this? Well, it’s an interesting metric that has been around for a number of years, and it’s heavily studied by a lot of people.

[Slide appears with on-screen text over white: Ecological Footprint = The human demand on the planet’s ability to provide renewable resources and ecological services. Takes into account biologically productive land and water required to sustain us relative to the global area that is available.]

CRACRAFT: It’s the human demand on the planet’s ability to provide renewable resources and ecological services. That is per every year. And it takes into account biologically productive land and water required to sustain us, relative to the global area that is available.

[Cracraft stands in front of podium, speaking to audience.]

CRACRAFT: And we measure this in global hectares. There’s hectares which everybody uses, a lot of people use in the world for a measure of area, but global hectares is special for this problem. It’s just how many global hectares do we all need to sustain ourselves around the world? 

[Slide with graph appears. Y-axis labeled “Ecological Footprint (number of planet Earths),” and ranging from 0 to 2. X-axis labeled with years from 1961 to 2008. Citation: From “Living Planet Report 2012.” By WWF International, Gland, Switzerland. 2012.]

CRACRAFT: So here is the 2008 footprint, from 1961 to 2008.

[Red circle appears around the number 1 on the y-axis. Red asterisk appears over the year 1970 on the x-axis. Line is drawn horizontally across the graph from 1 on the y-axis to the right end.]

CRACRAFT: Now I want to call attention to that one there, and that line that goes across, and that star there, 1970. That line that goes across is one Earth, one Earth. In 1970, we no longer were sustainable on one Earth. And as of 2008, it’s one and a half Earths. Now it’s around about 1.7 Earths. So it takes 1.7 Earths to provide us with- as sustainable, which means that we have an overshoot of about three quarters of an Earth.

[Cracraft stands in front of podium, speaking to audience.]

CRACRAFT: Three quarters of an Earth. So this trend is continuing. This is a good metric for telling us that we’re eating ourselves out of house and home. 

[Slide with graph titled, “Effects of Climate Change.” Six global heat maps represent decadal mean surface temperature anomalies for the years 1961-1970, 1971-1980, 1981-1990, 1991-2000, 2001-2010, and 2011-2015. As the years progress, the number of temperature anomalies increases greatly. Text under maps reads, “Relative to 1951-1980 base period.” Citation: From “Global Temperature in 2015.” By Hansen, et al. Goddard Institute for Space Studies, Columbia University Earth Institute, 2016.]

CRACRAFT: My third thing I want to talk about is climate change. This was just published not so long ago, a year ago, but what it’s doing is showing you the decadal mean surface temperature of the Earth. And so you look at the left-hand corner, 1961-1970; ’71-’80; ’81-’90; ’91-2000; 2001-2010; and the last five years. It doesn’t take anybody with one eye and half a brain to know what’s happening to the globe, right?  It’s just getting hotter and hotter and hotter. 

[Cracraft stands in front of podium, speaking to audience.]

CRACRAFT: Now this is going to cause serious problems. It is already causing serious problems, and I will mention that there are hundreds and hundreds of papers showing how global change, climate change, is affecting populations of organisms all over the globe, especially in the high altitudes and so on. 

But now this is the serious stuff.

[Slide appears with four maps of the United States titled, “Damages From Climate Change Across US Counties (2080-2099).” Upper left map is labeled, “Agriculture Shifts” and predicts that agricultural yields will grow in the northwestern part of the country, and greatly decrease in the Midwest and parts of the Southwest. The upper right map is labeled, “Mortality Shifts,” and predicts that mortality (change in deaths per 100k) will grow in the southeastern U.S., while remaining largely stable in the northern half of the country. Lower left map is labeled, “Energy Use Shifts,” and predicts that energy demand will grow in the southwest and southern states, while decreasing only in the Pacific Northwest and parts of New England. Lower right map is labeled, “Costs Increase Significantly,” and predicts total direct damages as a percentage of county GDP will increase in the southeastern states, while largely decreasing in the Northwest, upper Midwest, and New England. Citation: From “Estimating Economic Damage From Climate Change In the United States.” By Hsiang, et al. Science 30 Jun 2017 : 1362-1369. Reprinted with permission from AAAS.]

CRACRAFT: These are the damages that are—this is a very, very recent study in Science Magazine—about what are the damages across the U.S. counties. It’s down to the county level of between 2080 and 2099. So they had all this information of what happens over the years to people and to economies and so forth, and then they modeled it up to where the expectation is going to be, where we’re going to be, as business as usual. In other words, if we just keep doing what we’re doing.

So agricultural shifts, as you might expect, are all mostly going to go north, and some in the west. So everything green in this instance means negative damage and economic gains. So agriculture will shift. And most of the rest of the country is not going to be too terribly great for agriculture, or it’s going to be in that light area, neutral.

Then we look at mortality shifts. So you can see the dark, dark red, that’s where mortality is going to go up. And it’s based on empirical data of what happens here in the States right now over years when mortality goes up. Energy use is going to shift. The southern part of the United States needs more electricity for more air conditioning. And the costs; these are the costs in GDP for each county. Now doesn’t it strike you that global climate change is going to hit the red states more than it’s going to hit the blue states? 

[Cracraft stands in front of podium, speaking to audience.]

CRACRAFT: Now, why do we have this disconnect in this country? Even if this thing is 30 percent wrong, that means that your kids and their kids are going to have a very, very different world.

Now the political system, economic system that the globe has, has yielded extreme wealth and lots of stuff for all of us. But half of the world, about 3.7 billion, live on less than $3 a day. Now many of those live okay, but they don’t have access to all kinds of stuff that the rest of the world have. So we have one half of the people in this world like that. 

Now the rest of us, and those people, too, we’ve had a totally free lunch. Now I’d like to ask a simple question. Is there anybody—raise your hand if there is—is there anybody in this audience who knows for sure that everything they’re wearing was harvested in this country, manufactured in this country, and was bought? Is there anybody that knows for sure that that’s the case? One.  One.  So all the belt buckles, shoe leather, everything you have?  But there’s one. This is a big audience. 

So this is global. And what we call externalities economically, is that we have a free lunch in that we don’t share in the cost, the environmental cost, in countries or even in our own country, for extracting all those goods out and then turning them into products and then moving them around the globe. So there’s local environmental costs and there’s local social costs for people that are exposed to mines and pollution and stuff like that, that we cause by buying it. Now we, again, is everybody that gets all this stuff.  

So externalities become really important if we’re trying to think about solutions. And these are services that we don’t pay for in general, even in this country.  

Now I’ve got to end. They don’t want me to keep going on and on. So I want to say that there are many, many millions of people in this world trying to do good with the environment. There really are. And the more I’ve traveled over the years and gone to biodiversity convention meetings and stuff like that, you see the troops. So that’s a hope. 

And there are many corporations, local government bodies that are just striving to be sustainable, striving to deal with climate change. But as individuals, and I’ll speak for myself, I don’t think we give enough thinking, deep thinking, about our own individual footprints, and that is especially important in the wealthy areas of the world.  

Now one thing that would help would be to decrease material throughput into this gigantic consumption system. And if we externalize those costs of consumption, so if you build a big mine pit in the middle of Papua New Guinea in one of the richest biodiversity hotspots in the world, well, you’ll pay the local people a little bit, but none of that cost is sent downstream to us. And I’ve flown over there and just seen rivers coming out of these hills just yellow with chemicals in them. That’s a major, major health cost, environmental cost, that we don’t share in. 

So externalizing thinking about how to do that is important. But as a whole bunch of people, and I’ve really delved into a lot of this in recent months- 

[Slide with text over white screen reads: “Ultimately, major transformative changes in the global economy are necessary to reduce humanity’s environmental footprint to sustainable levels.” We need to find a prosperous way down. Citation: From “Estimating Economic Damage From Climate Change in the United States.” By Arjen Y. Hoekstra, Thomas O. Wiedmann, Science 06 Jun 2014 : 1114. Reprinted with permission from AAAS.] 

CRACRAFT: Ultimately, major transformative changes in the global economy are necessary to reduce humanity’s environmental footprint to sustainable levels. And we need, as some of these economists say, we need to find a prosperous way down. 

[Cracraft stands in front of podium, speaking to audience.] 

CRACRAFT: And we better do it, because the only biodiverse planet in the universe is right here.  And the question is, are we going to blow it or not?  

Thanks very much.

[APPLAUSE]

[Photo of the Museum’s Hall of Biodiversity appears.]

[On-screen text: The SciCafe series is proudly sponsored by Judy and Josh Weston.]

[Credits roll.]