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All IPCC definitions taken from Climate Change 2007: The Physical Science Basis. Working Group I Contribution to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Annex I, Glossary, pp. 941-954. Cambridge University Press.

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Climate Hustle

Can animals and plants adapt to global warming?

What the science says...

A large number of ancient mass extinction events have been strongly linked to global climate change. Because current climate change is so rapid, the way species typically adapt (eg - migration) is, in most cases, simply not be possible. Global change is simply too pervasive and occurring too rapidly.

Climate Myth...

Animals and plants can adapt
[C]orals, trees, birds, mammals, and butterflies are adapting well to the routine reality of changing climate." (source: Hudson Institute)

Humans are transforming the global environment. Great swathes of temperate forest in Europe, Asia and North America have been cleared over the past few centuries for agriculture, timber and urban development. Tropical forests are now on the front line. Human-assisted species invasions of pests, competitors and predators are rising exponentially, and over-exploitation of fisheries, and forest animals for bush meat, to the point of collapse, continues to be the rule rather than the exception.

Driving this has been a six-fold expansion of the human population since 1800 and a 50-fold increase in the size of the global economy. The great modern human enterprise was built on exploitation of the natural environment. Today, up to 83% of the Earth’s land area is under direct human influence and we entirely dominate 36% of the bioproductive surface. Up to half the world’s freshwater runoff is now captured for human use. More nitrogen is now converted into reactive forms by industry than all by all the planet’s natural processes and our industrial and agricultural processes are causing a continual build-up of long-lived greenhouse gases to levels unprecedented in at least the last 800,000 years and possibly much longer.

Clearly, this planet-wide domination by human society will have implications for biological diversity. Indeed, a recent review on the topic, the 2005 Millennium Ecosystem Assessment report (an environmental report of similar scale to the Intergovernmental Panel on Climate Change Assessment Reports), drew some bleak conclusions – 60% of the world’s ecosystems are now degraded and the extinction rate is now 100 to 1000 times higher than the “background” rate of long spans of geological time. For instance, a study I conducted in 2003 showed that up to 42% of species in the Southeast Asian region could be consigned to extinction by the year 2100 due to deforestation and habitat fragmentation alone.

Figure 1: Southeast Asian extinctions projected due to habitat loss (source: Sodhi, N. S., Koh, L. P., Brook, B. W. & Ng, P. K. L. 2004)

Given these existing pressures and upheavals, it is a reasonable question to ask whether global warming will make any further meaningful contribution to this mess. Some, such as the sceptics S. Fred Singer and Dennis Avery, see no danger at all, maintaining that a warmer planet will be beneficial for mankind and other species on the planet and that “corals, trees, birds, mammals, and butterflies are adapting well to the routine reality of changing climate”. Also, although climate change is a concern for conservation biologists, it is not the focus for most researchers (at present), largely I think because of the severity and immediacy of the damage caused by other threats.

Global warming to date has certainly affected species’ geographical distributional ranges and the timing of breeding, migration, flowering, and so on. But extrapolating these observed impacts to predictions of future extinction risk is challenging. The most well known study to date, by a team from the UK, estimated that 18 and 35% of plant and animal species will be committed to extinction by 2050 due to climate change. This study, which used a simple approach of estimating changes in species geographical ranges after fitting to current bioclimatic conditions, caused a flurry of debate. Some argued that it was overly optimistic or too uncertain because it left out most ecological detail, while others said it was possibly overly pessimistic, based on what we know from species responses and apparent resilience to previous climate change in the fossil record – see below.

A large number of ancient mass extinction events have indeed been strongly linked to global climate change, including the most sweeping die-off that ended the Palaeozoic Era, 250 million years ago and the somewhat less cataclysmic, but still damaging, Palaeocene–Eocene Thermal Maximum, 55 million years ago. Yet in the more recent past, during the Quaternary glacial cycles spanning the last million years, there were apparently few climate-related extinctions. This curious paradox of few ice age extinctions even has a name – it is called ‘the Quaternary Conundrum’.

Over that time, the globally averaged temperature difference between the depth of an ice age and a warm interglacial period was 4 to 6°C – comparable to that predicted for the coming century due to anthropogenic global warming under the fossil-fuel-intensive, business-as-usual scenario. Most species appear to have persisted across these multiple glacial–interglacial cycles. This can be inferred from the fossil record, and from genetic evidence in modern species. In Europe and North America, populations shifted ranges southwards as the great northern hemisphere ice sheets advanced, and reinvaded northern realms when the glaciers retreated. Some species may have also persisted in locally favourable regions that were otherwise isolated within the tundra and ice-strewn landscapes. In Australia, a recently discovered cave site has shown that large-bodied mammals (‘megafauna’) were able to persist even in the arid landscape of the Nullarbor in conditions similar to now.

However, although the geological record is essential for understanding how species respond to natural climate change, there are a number of reasons why future impacts on biodiversity will be particularly severe:

A) Human-induced warming is already rapid and is expected to further accelerate. The IPCC storyline scenarios such as A1FI and A2 imply a rate of warming of 0.2 to 0.6°C per decade. By comparison, the average change from 15 to 7 thousand years ago was ~0.005°C per decade, although this was occasionally punctuated by short-lived (and possibly regional-scale) abrupt climatic jolts, such as the Younger Dryas, Dansgaard-Oeschger and Heinrich events.

B) A low-range optimistic estimate of 2°C of 21st century warming will shift the Earth’s global mean surface temperature into conditions which have not existed since the middle Pliocene, 3 million years ago. More than 4°C of atmospheric heating will take the planet’s climate back, within a century, to the largely ice-free world that existed prior to about 35 million years ago. The average ‘species’ lifetime’ is only 1 to 3 million years. So it is quite possible that in the comparative geological instant of a century, planetary conditions will be transformed to a state unlike anything that most of the world’s modern species have encountered.

C) As noted above, it is critical to understand that ecosystems in the 21st century start from an already massively ‘shifted baseline’ and so have lost resilience. Most habitats are already degraded and their populations depleted, to a lesser or greater extent, by past human activities. For millennia our impacts have been localised although often severe, but during the last few centuries we have unleashed physical and biological transformations on a global scale. In this context, synergies (positive or self-reinforcing feedbacks) from global warming, ocean acidification, habitat loss, habitat fragmentation, invasive species, chemical pollution (Figure 2) are likely lead to cascading extinctions. For instance, over-harvest, habitat loss and changed fire regimes will likely enhance the direct impacts of climate change and make it difficult for species to move to undamaged areas or to maintain a ‘buffer’ population size. One threat reinforces the other, or multiple impacts play off on each other, which makes the overall impact far greater than if each individual threats occurred in isolation (Brook et al 2008).

Figure 2: Figure from the Millennium Ecosystem Assessment

D) Past adaptation to climate change by species was mainly through shifting their geographic range to higher or lower latitudes (depending on whether the climate was warming or cooling), or up and down mountain slopes. There were also evolutionary responses – individuals that were most tolerant to new conditions survived and so made future generations more intrinsically resilient. Now, because of points A to C described above, this type of adaptation will, in most cases, simply not be possible or will be inadequate to cope. Global change is simply too pervasive and occurring too rapidly. Time’s up and there is nowhere for species to run or hide.

Intermediate rebuttal written by Daniel Bailey

Update July 2015:

Here are related lecture-videos from Denial101x - Making Sense of Climate Science Denial



Additional videos from the MOOC

Interviews with  various experts on Coral bleaching and Ocean acidification

Expert interview with Annamieke Van De Heuvel

(experiments in the lab on coral adaption)

Expert interview with Gregg Webb

(obtaining data in the field about past coral adaption)

Expert interview with Christine Hosking

(impacts of climate change on wildlife ecosystems.... research into koalas)

Expert interview with Charlie Veron

(on the notion that the oceans were (thought to be) indestructible)

Expert interview with Ove Hoegh-Guldberg

(overview of impacts on coral reefs)

Last updated on 11 October 2016 by pattimer. View Archives

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Further reading


This is a guest post by Professor Barry Brook, an international research leader in global ecology and conservation biology. He holds the Foundation Sir Hubert Wilkins Chair of Climate Change and is Director of the Research Institute for Climate Change and Sustainability at the University of Adelaide. He has published two books and over 120 scientific papers on various aspects of human impacts on the natural environment and biodiversity, including climate change, deforestation and overexploitation of populations. In 2006, he was awarded both the Australian Academy of Science Fenner Medal for distinguished research in biology and the Edgeworth David Medal by the Royal Society of New South Wales, and in 2007, the H.G. Andrewartha Medal by the Royal Society of South Australia and was listed by Cosmos as one of Australia's top 10 young scientists. The principal motivation for his research is to identify ways and means of reducing extinctions and mitigating the worst ravages of global change. Read more at Brave New Climate.


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Comments 51 to 63 out of 63:

  1. Re: Anthony's post about Candian geese, @50: Here in Colorado we refer to them as 'illegal residents.' They are also here now, year-round, and I clearly remember this not being the case 30+ years ago. No wonder: We feem them so well with our over-irrigated Kentucky blus grass lawns, and excessive non-native trees, coupled with the fact of shorter, warmer winters, they made the Adam Smith rational choice, and stayed over.

  2. Responding to tkman0 question asked here

    It's helpful if you provide sources to where you got your understanding to better understand the question. However, if you read the article above it should help. Ease of adaption depends on the rate of change. It takes time for suitable soils to develop for instance and the change is not merely about temperature but also changes in precepitation etc. Climate change does not affect hours of sunlight either.

  3. tkman0 asks elswhere:

    "I understand that plants might not necessarily migrate north as temperatures increase and as their climatic boundaries change, but why is that the case? If you could point me towards a page or two that explains it, it would be appreciated."

    Well, this page asserts it, but does not explain it.  Discussion is at least on topic here.  So:

    Tree ranges do in fact migrate with temperatures.  This has been well established from evidence of response to the warming at the end of the last glacial using data from pollen and other plant remains:

    It is also evident in Europe, where there are a large number of species confined to one or a few mountains, the result of gradual migration up the mountain slope as the Earth warmed with the consequent genetic isolation allowing the evolution of new species.

    Migration in response to AGW faces three major limitations.

    First, migration may simply be not physically possible.  The alpine species mentioned above, for example, have an obvious limit to their migration with increasing warming such that any whose lower altitude range is within 600 meters of the summit will go extinct with a regional temperature rise of 4 C.  Indeed, they may go extinct with a smaller temperature rise in that as the population approaches the summit, a smaller and smaller population can be supported leaving them vulnerable to extinction by chance fluctuations on population due to disease, predation or unusual weather.  Similar issues face species near northern coastlines (in the NH).  A regional rise in temperature of 4 C will do for (at least locally) most species whose southern limit is within 600 km of a northern coastline:


    In addition to these obvious bariers, east-west mountain ranges, or even large scale changes in underlying soil type can present natural bariers to migration, and hence potential exinction threats.

    More importantly in the modern world is that human activity has created a very large number of additional bariers to migration (the second limitation).  Put simply, seeds from trees that land in cornfields do not grow to maturity.  Nor, come to that, do they typically grow to maturity in pasturage.  The vast farmlands developed by humans across the NH represent a major barier to the migration of the range of trees.

    Finally, and most importantly, the third barrier is the simple pace of temperature change.  We are currently facing an increase of temperature of about 3 C over the coming century.  That equates to a distance of about 450 km of change in latitudinal range to preserve current species health.  Trees that propogate by dropping  seeds can change there range at a few hundred meters per generation at most.  (They can do so much faster if the seeds are dispersed by birds, and to a lesser extent winds.)  Given the pace at which climate is changing, they well simply be left behind.  

    The effect will be complicated.  Intuitively that means their northern range will not expand as rapidly as their southern range retreats - but that is not necessarilly true.  For trees, like most life forms, the greatest competition comes from other species rather than from the environment itself.  This is shown by the shere range of environments in which trees protected from competition by being in gardens can grow.  It follows that the southern range will only retreat rapidly if some competitor species can advance quickly.  So the actual likely result (IMO) is that long lived, slow growing species will be displaced by short lived quick growing species across the range.  

  4. Thanks for the replies everyone, also just wanted to point out that some of the links on here dont link to articles, but insteasd link simply to a general climate change page at the univeristy of texas.

  5. tkman0

    The latest IPCC report has this graph about species movement rates vs warming rates

  6. There was an interesting find I saw published in the journal of Nature Communications published September 2014:Central Europe Tree Growth

    ...we show that, currently, the dominant tree species Norway spruce and European beech exhibit significantly faster tree growth (+32 to 77%), stand volume growth (+10 to 30%) and standing stock accumulation (+6 to 7%) than in 1960.


    That's interesting, a 75% increase in growth rate in beech trees in parts of Europe.

    My personal inclination is simply to work to manage forests responsibly.

  7. Protagorias,

    I saw an interesting find where it described that 25% of the trees in Texas over 4" diameter at breast height were killed by the drought they have had.   In California the current drought is the worst in the past 1200 or more years.  Fires alone have killed millions of trees.  Do you think the increase in trees in Central Europe is more or less than the decrease in trees in the American West?  What should we do to manage the forests more responsibly in the face of historic droughts?   

  8. Looking deeper I found this reference which is more reliable and suggests only about 5% of Texas trees were killed by the 2011 drought.  I stand by my point that managing forrests will produce little return in the face of historic drought.

  9. michael sweet,

    Climate change is undoubtedly happening at a very rapid and uncomfortable pace. And droughts are obviously a big concern.

    Perhaps what can produce a lot of return in the long run, be economocially sound jobs, as well as potentially help in managing forests and mitigating drought, is to gain the technology to unlock some of the water locked up the ringwoodite inside our planet. I think there's something like two or three times the volume of the world's oceans locked up in ringwoodite, but it's around 500 miles down.

  10. Once desertification takes hold it is an irreversible process. That is not to say the rain won't fall elsewhere yet where and in what proportion?

    The concept of non-linearity means there are no promises!

    Who can tell me if the economic rise of China has yet been reflected in the Keeling curve, for instance?

  11. To Anthony @50: Don't know much about birds but mentioning "migration" reminded me of a doco I saw the other night(about "song-birds" I think!?!) that said birds in the Northern hemisphere and the Southern hemisphere act differently. I think there may be a climatic reason to it but I can't remember what it was!

  12. This is appeal to nature fallacy. Just because some species exist, doesnt mean it's necessarily good that they continue to exist. Also, "animals/plants can adapt" doesnt necessarily mean every specie will adapt. it means life in general will adapt and create new forms of animals who, guess what, can now survive in the new climate. Throughout history catastrophic events changed entire climate of the planet in a day. and yet life survived, and flourished. So this entire appeal to nature fallacy is wholly uninteresting to me.

  13. guad,

     You are factually incorrect. An appeal to nature is an argument or rhetorical tactic in which it is proposed that "a thing is good because it is 'natural', or bad because it is 'unnatural'".

    Whereas this article focuses on actual things that are bad...because they would be bad whether natural or not. Ecosystems have functions. We call this ecosystem services. You might want to read up on it, since it is what keeps you alive. Ecosystem services

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