Species and Ecosystem Emergencies
A key paper for the IPCC ecological assessment AR4 and AR5 (supported) is by C. Thomas Extinction Risks from Climate Change.

​​As we are fixed on the worst case emissions scenario and habitat loss continues unabated the actual projected extinction rate based from the Thomas paper is much worse than has been reported.
​It is 33% with dispersal benefit of species and 58% with no dispersal. Because the rate of climate change is unprecedented ​for the vast ​majority f species the 58% must be assumed most likely.
Assessing for risk the 58% would be the figure used.​

We are on a fixed heading for a global warming of 6C by 2100 (International Energy Agency) and a possible 4°C warming by 2060 (R. Betts 2011) . A World Bank reports shows ​we are also committing ourselves to a 4°C warming. The IPCC 2007 assessment found that As global average temperature increase exceeds about 3.5°C (i.e. 4°C from pre-industrial), model projections suggest significant extinctions (40 to 70% of species assessed) around the globe.

Obviously we can expect polar, mountaintop and desert ecosystems and biodiversity to suffer large losses with even small degrees of warming. ​The Amazon is the greatest home of natural bio diversity and it may be particularly vulnerable to global warming, because it makes its own self sustaining weather.

Deforestation is both a cause and a result of global climate change​.
The 2014 IPCC AR5 ​reports Extensive tree mortality and widespread forest dieback (high mortality rates at a regional scale) linked to drought and temperature stress have been documented recently on all vegetated continents. Long-term increasing tree mortality rates associated with temperature increases and drought have been documented in boreal and temperate forests in western North America. Episodes of widespread die-back have been observed in multiple vegetation types, particularly in western North America, Australia, and southern Europe (AR5 WG2 Box 4.2, Fig 4.7)

Deforestation contributes 6–17% CO2 emissions (A. Baccini et al Nature 2012)
"​Trees: our life savers are dying" (US) July 2013 The Guardian Jim Robbins
​Oct 2013 Climate change affecting North American forests, researchers find.

FAO 2011 literature review Forests and Climate Change

​​As far back as ​​2000 Peter Cox published a model result (Acceleration of global warming due to carbon-cycle feedbacks in a coupled climate model) finding a high terrestrial carbon feedback warming of an added 1.5C by 2100 mostly due to a predicted Amazon die-back. The die-back results from increased Amazon drought and drying.

We find that under a 'business as usual' scenario, the terrestrial biosphere acts as an overall carbon sink until about 2050, but turns into a source thereafter. By 2100, ... atmospheric CO2 concentrations are 250 p.p.m.v. higher in our fully coupled simulation than in uncoupled carbon models, resulting in a global-mean warming of 5.5 K, as compared to 4 K without the carbon-cycle feedback.

Other models have been published without Amazon die back and lower terrestrial carbon feedback warming (0.5C). Field research since 2000 tends to confirm the risk of catastrophic die back under warming real. The carbon cycle modeling on the other hand suggests that high CO2 fertilization will protect the Amazon from global warming heat and drying, but if the assumed CO2 fertilization does not happen die back will. 
IUCN  2013  press release, the IUCN has updated its Red List  of species by conservation status. This update reports about a third of assessed speciescurrently considered threatened or endangered. Among the most dramatic changes is that a full third of all known conifer species are now considered threatened or endangered. 
Natural Resources Canada published the first review of global tree mortality due to climate causes. Their report shows that increased tree dieback may occur in many areas and is already occurring in some areas.
Many other forested regions will be damaged or lost by global climate change.  A recent study shows that some forested areas that are becoming drier due to global climate change are no longer able to regenerate following forest fires. Instead, these areas grow back with other, non-forest communities. Trees, like many other organisms, are much more vulnerable when young, so that adult trees can persist in conditions too harsh for seedlings to live. This means that some sites that are currently forested will also be permanently deforested if struck by a major forest fire. Since increased fire frequency is also a likely consequence for climate change, sooner or later these areas will burn. 
Two Severe Amazon Droughts in Five Years (2005, 2010) 2011 study alarms Scientists. ​The 2010 Amazon Drought.  S.L. Lewis Science, 2011

A special 2011 UNEP report ​​Drought, Fire and Deforestation in the Amazon:
Feedbacks, Uncertainty and the Precautionary Approach, covered the issue.

​In particular is this 2013 released NASA study Severe Climate Jeopardizing Amazon Forest. The published paper source is here. Nature 2012 Severe drought has lasting effects on Amazon Satellite data reveal effects of climate change on tropical forests. An area of the Amazon rainforest twice the size of California continues to suffer from the effects of a megadrought that began in 2005, finds a new NASA-led study. These results, together with observed recurrences of droughts every few years and associated damage to the forests in southern and western Amazonia in the past decade, suggest these rainforests may be showing the first signs of potential large-scale degradation due to climate change. The record shows Amazon is experiencing a drought rate that is unprecedented in a century

It was discovered that billions of trees died after the 2010 Amazon drought. 

​Simon Lewis one of the study authors, a forest ecologist at the University of Leeds in Great Britain, commented - 'those two unusual events are consistent with those predictions that suggest that the Amazon may be severely impacted over the next few decades by these droughts,"

Another NASA observation reported 2013 finds Hidden Wildfires Taking Big Toll on Amazon Rainforest . These understorey below canopy in several years have affected several times more rainforest than intentional clearing.
A 2004 Royal Society paper Contrasting simulated past and future responses of the Amazonian forest to atmospheric change​​ concluded We speculate that the Amazonian forest is currently near its critical resiliency threshold, and that "even minor climate warming may be sufficient to promote deleterious feedbacks on forest integrity."
2015 research shows the Amazon and Boreal Forests face climate change tipping points.

IPCC 2014 AR5 WG2 Forests will be unable ​migrate to avoid climate change impacts and regional forest ecosystem transformation 

​9 July 2013 — Global Climate Change Extinction. To survive global climate change this century, most vertebrate species would have to evolve about 10,000 times faster than they have in the past to adapt to the extreme speed of projected climate change University of Arizona research
2 Aug 2013 Science Stanford review reports that ecosystem climate changes will intensify in the coming decades, unfolding at a rate that is potentially several orders of magnitude—more rapid than the changes to which terrestrial ecosystems have been exposed during the past 65 million years. The combination of high climate-change velocity and multidimensional human fragmentation will present terrestrial ecosystems with an environment that is unprecedented in recent evolutionary history.
Ecosystem danger limit 1.0-1.5°C (global average from pre-industrial)

"Earlier IPCC reports described several ecosystems to be resilient to warming up to 1°C.  ​​During the course of this century the resilience of many ecosystems (their ability to adapt naturally) is likely to be exceeded by an unprecedented combination of change in climate, associated disturbances (e.g., flooding, drought, wildfire, insects, ocean acidification) and in other global change drivers (especially land-use change, pollution and over-exploitation of resources), if greenhouse gas emissions and other changes continue at or above current rates (high confidence).

​​Many significant impacts of climate change may emerge through shifts in the intensity and the frequency of extreme weather events. Extreme events can cause mass mortality of individuals and contribute significantly to determining which species occur in ecosystems

Despite the recognized importance of multiple drivers of ecosystem change, they are rarely all included in current climate and ecosystem models used for assessing climate change impacts on ecosystems. The explicit inclusion of non-climatic drivers and their associated interactions in analyses of future climate change impacts could lead to unexpected outcomes. Consequently, many impact studies of climate change that ignore land-use and other global change trends may represent inadequate estimates of projected ecosystem responses." 
IPCC AR4 2007
The prevention of damage to global ecosystems beyond their resilience is a provision in the 1992 UN climate convention.

​​That limit was assessed at 1.0°C back in 1990 because 'Temperature Increases beyond 1C may elicit rapid unpredictable and non linear responses that could lead to extensive ecosystem damage. (Rijsberman, F. R. & Swart, R. J. Targets and Indicators of Climatic Change Stockholm Environment Institute, 1990).

The 2°C policy target is global ecological catastrophe from the IPCC AR4 data. ​​The long term target is now 1.5°C.

The map is from Mapping vulnerability and conservation adaptation strategies under climate change   James E. M. Watson, Sept 2013 Nature Climate Change ' The relationship between intactness (adaptive capacity) and stability (exposure) varies widely across ecoregions, with some of the most vulnerable, according to this measure, located in southern and southeastern Asia, western and central Europe, eastern South America and southern Australia.
The 2005 Exeter Dangerous Climate Change conference confirmed the  long held opinion that 1 to 1.5°C at a warming rate limit of 0.5°C per century ​is the danger limit for species and ecosystems.
​The conference published a comprehensive table of the ecology and rising degrees of warming.
Projected future climate change and other human-induced pressures are virtually certain to be unprecedented  compared with the past several hundred millennia    (IPCC AR4 WG2 Ch4 1.2 Key Issues)

Climate Emergency Institute

As in general global climate change will​ harm wildlife directly and exacerbate ongoing harm that has lead to the 6th planetary mass extinction even. 

​​6th mass extinction
Global climate change is now impacting on top of the 6th mass extinction

S​pecies being wiped out at 1000 X natural rate Pimm May 2014  mainly caused by habitat destruction and invasive species. Global climate change will lead to habitat damage and destruction, making species seeking new habitats  'alien'.

​​The 2016 WWF Living Planet Index finds global populations of fish, birds, mammals, amphibians and reptiles declined by 58 per cent between 1970 and 2012.

The 2014 IPCC AR5 reports Climate change rate exceeds large extinctions in the past millions of years. Natural global climate change at rates slower than current anthropogenic climate change caused significant ecosystem shifts and species extinctions during the past millions of years. (AR5 WG2 p. 4)
A large fraction of both terrestrial and freshwater species faces increased extinction risk under projected climate change during and beyond the 21st century, especially as climate change interacts with other stressors. [CURRENT RATE OF EXTINCTION IS 100 x NATURAL BACKGROUND RATE: S. Pimm, Science, May 2014.] Extinction risk is increased under all RCP scenarios, with risk increasing with both magnitude and rate of climate change. (AR5 WG2 SPM p. 14).

A large fraction of the species assessed is vulnerable to extinction due to climate change, often in interaction with other threats. Species with an intrinsically low dispersal rate, especially when occupying flat landscapes where the projected climate velocity is high, and species in isolated habitats such as mountaintops, islands, or small protected areas are especially at risk. Cascading effects through organism interactions, especially those vulnerable to phenological changes, amplify risk (high confidence (AR5 WG2 Table TS4).

​​The AR5 ​​uses only the crude speed a species can move to escape increasing degrees of global warming (not the full climate disruption). Obviously, as also recorded in AR5, there many other adverse climate change effects.

​​Even so the shocking AR5 finding is that trees and plants in general lose favorable climate space (AR5) by 2.0°C global warming. They cannot escape or adapt to the rate of warming affecting their health and supporting ecosystems from a 2.0°C global warming (N.B. local land warming is higher than global warming).  AR5- Losing favorable climate space is projected to lead to reduced fitness, declining abundance, and local extinction, with potentially large effects on biodiversity and ecosystem services (see evidence of early signs of this widespread tree mortality). On top of losing climate space, climate change causes increasing drying & drought, insect infestation, forest fires and supportive species mismatches, making the situation very much worse. Most trees and plants cannot be expected to survive 2°C.

Only the best case emissions scenario RCP2.6 give tree and plant species a chance of surviving climate change. All other scenarios are above 2.0°C by 2100.
The impact on tree survival (among other species)will be even more under-estimated due to establishment in a new location. AR5- ​​Estimates of tree displacement rates are frequently based on models or observations of dispersal of seeds controlling establishment of adult trees. Displacement rates of trees are often more strongly limited by establishment than dispersal. Limits on establishment could also be important for other species groups, but often only dispersal rates have been calculated, leading to an overestimation of displacement rates. (AR5 WG2 -298). 

​AR5-Many papers published since AR4 argue that the uncertainty may be even higher than indicated in syntheses of model projections, due to limitations in the ability of current models to evaluate extinction risk. Models frequently do not account for ​dispersal capacity, population dynamics, the effects of habitat fragmentation and loss and community interactions. (AR5 (WG2 -298)

Community interactions not in the models ​​includes what is today the largest cause of species extinctions, which is deforestation and ecosystem alien species. The further large loss of forests will drive populations and species extinctions faster than estimated by climate space models, and even species that can move fast will be alien species.  

AR5 reports ​​​​​Extensive tree mortality and widespread forest die-back (high mortality rates at a regional scale) linked to drought and temperature stress have been documented recently on all vegetated continents​​.
​long-term increasing tree mortality rates associated with temperature increases and drought have been documented in boreal and temperate forests in western North America. Episodes of widespread die-back (high mortality rates at a regional scale) have been observed in multiple vegetation types, particularly in western North America, Australia, and southern Europe. (AR5 WG2 Box 4-2 Tree Mortality and Climate Change).
​In addition forest fires are increasing and will be widespread by 1.8°C global warming. 
8 Dec 2016 Climate-Related pant & animal local extinctions already Widespread  
​​10 Nov 2016Climate change already dramatically disrupting all elements of nature.
A Glikson 2013 Past extinctions - climate 
May 2017 'Biological Annihilation' Rapidly increasing rate of  ​species extinctions 
Double Feedback Global climate change will boost today's already 6th Earth mass extinction event and cause damage to ecosystems which will increase global climate change
by reduction of CO2 uptake. ​ 

'​​Extensive tree mortality and widespread forest dieback (high mortality at regional scale) linked to drought and temperature stress have been documented recently on all vegetated continents' (IPCC 2014 WG2 Box 4.2)

23 March 2018 Huge assessment  Destruction of nature ... ​threatens food and water security of billions of people, major UN-backed biodiversity study reveals  IPBES report 
Comprehensive Information 6th Mass Extinction
May 2017 warming associated with population decline of terrestrial birds & mammals globally  
VIDEO Oct 2018 ​​Insects vanish all over world
2019 Biodiversity & climate change My book chapter​
13 Nov 2018   'Co-extinctions annihilate planetary life during extreme environmental change'
May 2015 Global climate change will further accelerate extinctions. Accelerating extinction risk from climate change, Mark C. Urban
IPBES May 2019   UN assessment Nature’s Dangerous decline Unprecedented Extinction Rates -Accelerating BBC ​(charts) Nature's Emergency
15 May 2019 Deadly Cascade
August 2019 WWF calls Planetary Emergency
13 Dec 2019 Pervasive human-driven decline of life on Earth needs (immediate) transformative change
1996 Richard Leakey The Sixth Extinction: Patterns of Life & the Future of Humankind
1 Sept 2021.  30% of the world’s trees are at risk of extinction.
20 Dec 2021 Plant development mismatch under climate change 
potentially devastating to land life​
Jan 2022 How the speed of climate change is unbalancing the insect world
IPCC AR6 Fact sheet Biodiversity 
2022 WWF ​Wildlife populations have plummet by 69%