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Current State of Scientific Understanding of Climate Change Bob Watson.

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Presentation on theme: "Current State of Scientific Understanding of Climate Change Bob Watson."— Presentation transcript:

1 Current State of Scientific Understanding of Climate Change Bob Watson

2 Part I Climate Change and Projected Impacts

3 Most (greater than 50%) of the Observed Warming of the Last 50 Years is Attributable to Human Activities (a) Observed and modeled changes disagree between 1950 and 2000 with natural forcing alone (b) observed and modeled changes disagree between 1920 and 1970 with anthropogenic forcing alone ( c) Observed and modeled changes in are in good agreement with natural and anthropogenic forcing

4 Climate Change Climate change is both a development and global environmental issue, which undermines:Climate change is both a development and global environmental issue, which undermines: environmental sustainabilityenvironmental sustainability poverty alleviation and the livelihoods of the poorpoverty alleviation and the livelihoods of the poor human healthhuman health national and regional securitynational and regional security Climate change is an inter- and intra-generational equity issue:Climate change is an inter- and intra-generational equity issue: developing countries and poor people in developing countries are the most vulnerabledeveloping countries and poor people in developing countries are the most vulnerable the actions of today will affect future generations because of the long life-times of the greenhouse gases and the inertia within the climate systemthe actions of today will affect future generations because of the long life-times of the greenhouse gases and the inertia within the climate system

5 Atmospheric composition Since the industrial era began, human activities have increased the atmospheric concentrations of greenhouse gases, which tend to warm the Earth, and sulfate aerosols, which tend to cool the Earth, primarily due to energy and land management practices

6 Climate Change The Earths climate has changed, in part due to human activities, and is projected to continue to change, globally and regionally:The Earths climate has changed, in part due to human activities, and is projected to continue to change, globally and regionally: Warmer temperaturesWarmer temperatures Changing precipitationChanging precipitation Higher sea levelsHigher sea levels Retreating glaciersRetreating glaciers Reduced arctic sea iceReduced arctic sea ice More frequent extreme weather eventsMore frequent extreme weather events heat waves, floods and droughts heat waves, floods and droughts

7 Surface Temperature Projected changes from 1990 to 2100 Projected changes from 1990 to 2100 A mid-range projection of change from 1990 to 2100 – a global average of 3.1 o C The full projected range for changes in global average temperature is 1.4 o C to 5.8 o C Observed changes from 1976 to 1999

8 Precipitation Projected changes in precipitation from 1990 to 2100 Observed changes in precipitation from 1900 to 2000

9 Extreme Weather Events Model Prediction Confidence in Observed Change Higher maximum temperatures and more hot days66-90% Higher minimum temperatures, fewer cold days and frost days over nearly all land areas 90-99% Reduced diurnal temperature range over most land areas90-99% Increased heat index over most land areas90-99% More intense precipitation events over many areas90-99% Increased summer continental drying and associated risk of drought – mid-latitude continental interiors66-90%

10 Recent Findings Compared to the IPCC TAR, there is greater clarity and reduced uncertainty about the impacts of climate change Compared to the IPCC TAR, there is greater clarity and reduced uncertainty about the impacts of climate change A number of increased concerns have arisen: A number of increased concerns have arisen: Increased oceanic acidity likely to reduce the oceans capacity to absorb carbon dioxide and effect the entire marine food chainIncreased oceanic acidity likely to reduce the oceans capacity to absorb carbon dioxide and effect the entire marine food chain A regional increase of 2.7 o C above present (associated with a temperature rise of about 1.5 o C above today or 2 o C above pre- industrial level) could trigger a melting of the Greenland ice-capA regional increase of 2.7 o C above present (associated with a temperature rise of about 1.5 o C above today or 2 o C above pre- industrial level) could trigger a melting of the Greenland ice-cap An increase in ocean surface temperature of 1 o C is likely to lead to extensive coral bleachingAn increase in ocean surface temperature of 1 o C is likely to lead to extensive coral bleaching Reversal of the land carbon sink – possible by the end of the CenturyReversal of the land carbon sink – possible by the end of the Century Possible destabilization of the Antarctic ice sheets becomes more likely above 3 o C – the Larson B ice shelve is showing signs of instabilityPossible destabilization of the Antarctic ice sheets becomes more likely above 3 o C – the Larson B ice shelve is showing signs of instability The North Atlantic Thermohaline Circulation may slow down or even shut downThe North Atlantic Thermohaline Circulation may slow down or even shut down

11 Climate change is already affecting natural and social systems

12 The poor will face the greatest challenges from climate change. 2 Billion people in developing countries were affected by a climate related disaster in the 1990s. The rate has double in this decade 40 to 80% of the population in developing countries versus a few % in more developed countries

13 year % rainfall variability GDP growth Ag GDP growth Ethiopia A water rich developing country, but with GDP still tied to yearly rainfall variations Preliminary results from : A Country Water Resources Assistance Strategy for Ethiopia From Claudia Sadoff Climate variability is already a major impediment to development.

14 WHO estimates that >150,000 people are dying each year due to climate change

15 Wheat now being grown in areas 2 C cooler and 4.5 C warmer than in the 1920s. Shows rapid adaptation in wheat Pew

16 Climate change is a development issue – right now and will become even more so in the future

17 Climate Change Human-induced climate change is projected to: Decrease water availability and water quality in many arid- and semi-arid regions – increased risk of floods and droughts in many regions Decrease water availability and water quality in many arid- and semi-arid regions – increased risk of floods and droughts in many regions Decrease the reliability of hydropower and biomass production in some regions Decrease the reliability of hydropower and biomass production in some regions Increase the incidence of vector- (e.g., malaria and dengue) and water-borne (e.g., cholera) diseases, as well as heat stress mortality, threats nutrition in developing countries, increase in extreme weather event deaths Increase the incidence of vector- (e.g., malaria and dengue) and water-borne (e.g., cholera) diseases, as well as heat stress mortality, threats nutrition in developing countries, increase in extreme weather event deaths Decrease agricultural productivity for almost any warming in the tropics and sub-tropics and adverse impacts on fisheries Decrease agricultural productivity for almost any warming in the tropics and sub-tropics and adverse impacts on fisheries Adversely effect ecological systems, especially coral reefs, and exacerbate the loss of biodiversity Adversely effect ecological systems, especially coral reefs, and exacerbate the loss of biodiversity

18 % change in runoff by 2050 Many of the major food-bowls of the world are projected to become significantly drier

19 Crop yields are projected to decrease in the tropics and sub-tropics, but increase at high latitudes Percentage change in average crop yields for a mid-range climate change scenario Even as soon as 2020 crop yields in SSA and parts of Asia are projected to decrease by up to 20%

20 Climate change will exacerbate the loss of biodiversity Estimated 10-15% of the worlds species will be committed to extinction over next 30 years independent of climate change Biodiversity underlies all ecological goods and services – provisioning, regulating, supporting and cultural

21 Climate Change and Conflict Tens of millions of people displacedTens of millions of people displaced Low lying deltaic areas Low lying deltaic areas Small Island States Small Island States Food shortages where there is hunger and famine todayFood shortages where there is hunger and famine today Water shortages in areas already with water shortagesWater shortages in areas already with water shortages Natural resources depleted (e.g., coral reefs, forests), loss of ecological goods and servicesNatural resources depleted (e.g., coral reefs, forests), loss of ecological goods and services Increased incidence of diseaseIncreased incidence of disease Increased incidence of severe weather eventsIncreased incidence of severe weather events Climate Change, coupled with other local and global environmental issues can lead to local and regional conflict

22 Part II Political Situation and Adaptation and Mitigation

23 The Kyoto Protocol The Kyoto Protocol All industrialized governments, except the US and Australia have ratified the Kyoto Protocol, which contains: A commitment to reduce GHG emissions, on average, by about 5% between relative to 1990 The flexibility mechanisms – carbon trading Land-use, land-use change and forestry activities Funding mechanisms to assist developing countries The US stated that the Kyoto Protocol was flawed policy because it was neither fair nor effective and not in the best interests of the US scientific uncertainties – Article 3 (precautionary principle) high compliance costs – inconsistent with IPCC ineffective without the participation of the large developing countries

24 Beyond Kyoto Without the US taking real action to limit their GHG emissions it is doubtful that there will be a second commitment period – some OECD countries will withdraw and large developing countries, i.e., China and India will not be willing consider any commitmentsWithout the US taking real action to limit their GHG emissions it is doubtful that there will be a second commitment period – some OECD countries will withdraw and large developing countries, i.e., China and India will not be willing consider any commitments Without a commitment of governments to limit GHG emissions beyond 2012 (the end of the first commitment period) the carbon market will remain soft and the private sector is unlikely to enter in a meaningful mannerWithout a commitment of governments to limit GHG emissions beyond 2012 (the end of the first commitment period) the carbon market will remain soft and the private sector is unlikely to enter in a meaningful manner The real question for governments is whether to:The real question for governments is whether to: set an emissions target for a second commitment period ( ) or whether to set a long-term stabilization target for climate change (e.g., 2 o C above the pre-industrial level) or some other long-term frameworkset an emissions target for a second commitment period ( ) or whether to set a long-term stabilization target for climate change (e.g., 2 o C above the pre-industrial level) or some other long-term framework this would require a global emissions target – the challenge would be to agree on intermediate emissions targets and an equitable allocation of emissions rightsthis would require a global emissions target – the challenge would be to agree on intermediate emissions targets and an equitable allocation of emissions rights

25 Warming resulting from different stabilized concentrations of greenhouse gases pre-industrialized level ppm, current level ppm Even if the atmospheric concentration of carbon dioxide was stabilized at todays level, the Earths temperature would still increase by over 0.5 o C The atmospheric concentration of carbon dioxide equivalent (i.e., taking into account other GHGs) is close to 450ppm. The figure demonstrates that even if the atmospheric concentration of carbon dioxide was stabilized at ppm, a significant increase in temperature is projected, thus adaptation is an important part of a climate strategy Temperature change relative to 1990 (C ) Eventual CO 2 stabilisation level (ppm) Temperature change at equilibrium 2

26 Conclusions from Exeter Meeting Probability analysis suggests that to limit warming to 2 o C above pre-industrial levels with a relatively high certainty requires the equivalent concentration of carbon dioxide to stay below 400ppm Probability analysis suggests that to limit warming to 2 o C above pre-industrial levels with a relatively high certainty requires the equivalent concentration of carbon dioxide to stay below 400ppm Stabilization of the equivalent concentration of carbon dioxide at 450ppm would imply a medium likelihood of staying below 2 o C above pre-industrial levels Stabilization of the equivalent concentration of carbon dioxide at 450ppm would imply a medium likelihood of staying below 2 o C above pre-industrial levels If the equivalent concentration of carbon dioxide were to rise to 550ppm it is unlikely that warming would stay below 2 o C above pre-industrial levels If the equivalent concentration of carbon dioxide were to rise to 550ppm it is unlikely that warming would stay below 2 o C above pre-industrial levels The World Energy Outlook (2004) predicts that carbon dioxide emissions will increase by 63% over 2002 levels by This means that in the absence and urgent and strenuous actions to reduce GHG emissions in the next 20 years, the world will almost certainly be committed to a warming of between 0.5 o C and 2 o C relative to today by 2050, i.e., about 1.1 o C and 2.6 o C above pre- industrial The World Energy Outlook (2004) predicts that carbon dioxide emissions will increase by 63% over 2002 levels by This means that in the absence and urgent and strenuous actions to reduce GHG emissions in the next 20 years, the world will almost certainly be committed to a warming of between 0.5 o C and 2 o C relative to today by 2050, i.e., about 1.1 o C and 2.6 o C above pre- industrial

27 A climate risk approach Climate risk management means that we should assess and act upon, the threats and opportunities that result from both existing and future climate variability, including those deriving from climate change.

28 What can be done? Change farming systems Change farming systems Strengthen infrastructure Strengthen infrastructure Conserve natural buffers (eg forests including mangroves) Conserve natural buffers (eg forests including mangroves) Store more water Store more water Improve disaster preparedness Improve disaster preparedness Provide insurance? Provide insurance? Migrate Migrate But all have downsides

29 How are we going? A few developed countries are considering comprehensive adaptation plans Several studies suggest that about 40% of ODA projects & development loans are subject to some climate risk. But few (2%) consider climate risk in their design But everyone now wants to mainstream adaptation

30 Pitfalls to mainstreaming adaptation Not appreciating the immediacy Not appreciating the immediacy Projectisation of adaptation Projectisation of adaptation Sees adaptation as a series of projects but separates adaptation form core development planningSees adaptation as a series of projects but separates adaptation form core development planning Often embroils adaptation in institutional rivalriesOften embroils adaptation in institutional rivalries Poker chip in the climate negotiations Poker chip in the climate negotiations Seeking the ideal at the expense of the pragmatic Seeking the ideal at the expense of the pragmatic E.g. Seeking only adaptation – mitigation synergiesE.g. Seeking only adaptation – mitigation synergies Endless loop of better information Endless loop of better information Downscaling & impact modellingDownscaling & impact modelling

31 An adapted world A warmer world A warmer world More climate extremes and disasters More climate extremes and disasters Greater preparedness to deal with them Greater preparedness to deal with them More climate & water awareness (& more dams) More climate & water awareness (& more dams) Changed agricultural zones Changed agricultural zones Greater threats to and management of natural habitats Greater threats to and management of natural habitats Physical or natural barriers? Physical or natural barriers? Forced migration Forced migration

32 Potential Actions to Mitigate GHG Emissions Energy Efficiency and Conservation: Efficient vehicles, Reduced use of vehicles, Efficient buildings, and Efficient coal plant Fuel shift: Gas power for coal power CO 2 Capture and Storage: Capture CO 2 at power plant; Capture CO 2 at H 2 plant; Capture CO 2 at coal-to- synfuels plant; --- geological storage Nuclear fission: Nuclear power for coal power Renewable Electricity and Fuels: Wind power for coal power; PV power for coal power; Wind H 2 in fuel-cell car for gasoline in hybrid car; Biomass fuel for fossil fuel Forests and Agricultural Soils: Reduced deforestation, plus reforestation, afforestation and new plantations; and Conservation tillage

33 Policy Instruments Policies, which may need regional or international agreement, include: Policies, which may need regional or international agreement, include: Energy pricing strategies and taxesEnergy pricing strategies and taxes Removing subsidies that increase GHG emissionsRemoving subsidies that increase GHG emissions Internalizing the social costs of environmental degradationInternalizing the social costs of environmental degradation Tradable emissions permits--domestic and globalTradable emissions permits--domestic and global Voluntary programsVoluntary programs Regulatory programs including energy-efficiency standardsRegulatory programs including energy-efficiency standards Incentives for use of new technologies during market build-upIncentives for use of new technologies during market build-up Education and training such as product advisories and labelsEducation and training such as product advisories and labels Accelerated development of technologies requires intensified R&D by governments and the private sector Accelerated development of technologies requires intensified R&D by governments and the private sector

34 Clean Energy and Development: Towards an Investment Framework Covers three interlocking and complementary issues: the need for, and investment requirements of, meeting modern energy needs for developing countries over the long term in a manner that provides attention to efficiency and local environmental considerations; the additional steps needed in the energy, transport and industrial sectors to address climate change mitigation through the reduction of greenhouse gases; and the impact of climate change and the need for developing countries to adequately adapt to changes in climate and weather variability.

35 Conclusions Increased access to energy is critical for poverty alleviation and economic growthIncreased access to energy is critical for poverty alleviation and economic growth Climate change undermines development and environmental sustainabilityClimate change undermines development and environmental sustainability Access to affordable energy while also addressing climate change will require a collaborative effort involving governments, private sector, financial institutions, NGOs, and the research communityAccess to affordable energy while also addressing climate change will require a collaborative effort involving governments, private sector, financial institutions, NGOs, and the research community Increased public and private sector funding for energy S&TIncreased public and private sector funding for energy S&T Innovative public-private partnerships and technology transfer are neededInnovative public-private partnerships and technology transfer are needed The Bank can play a critical role in assisting client countries reduce GHG emissions and adapt to climate variability and changeThe Bank can play a critical role in assisting client countries reduce GHG emissions and adapt to climate variability and change Developing a robust carbon market can reduce emission reduction costs in OECD and improve access to new technologies in developing countries - carbon financing is a source of new financing (non-ODA)Developing a robust carbon market can reduce emission reduction costs in OECD and improve access to new technologies in developing countries - carbon financing is a source of new financing (non-ODA) There are cost-effective and equitable solutions, but political will and moral leadership is neededThere are cost-effective and equitable solutions, but political will and moral leadership is needed


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