GENV 2001 Notes - Climate Change PDF

Environmental Science, Scientific Uncertainty and the Politics of Climate Change  Types of Environmental Science Ecology & Environmental Biology; Environmental Chemistry & Toxicology; Environmental Geo-Science; Environmental Social Science.  How Science Contrib...

Environmental Science, Scientific Uncertainty and the Politics of Climate Change  Types of Environmental Science Ecology & Environmental Biology; Environmental Chemistry & Toxicology; Environmental Geo-Science; Environmental Social Science.  How Science Contributes to Environmental Studies… Helps us find & map environmental resources; Helps us monitor changes in the environment; Contributes to decision-making by improving our understanding of the relationships between the environment and human actions; Helps us to predict environmental consequences of human actions; New technologies may reduce human impacts on the environment; Influences public perception and may generate political will to address environmental problems; Provides objectivity and credibility to politically controversial decisions. The Challenge of Scientific Uncertainty Nature is complex: understanding is always tentative; Difficult to extrapolate from laboratory studies to the ‘real world’; Difficult to perform controlled experiments on large, natural systems, especially where humans are involved; Understanding may require long-term studies that are practically difficult to do;…  The Challenge of Scientific Uncertainty, cont’d. The environment is extremely varied in space: no two places are identical, so how compare one to another? The environment is constantly changing over time (daily, with the seasons, over longer periods), more so with human influences added. How compare the past to the present to the future? In summary: the world is extremely complex and there is a great deal of uncertainty about how it works. Science can rarely overcome all of these uncertainties. Environmental Science and Climate Change The Global “Greenhouse Effect”  The Greenhouse Gases CO2 = Carbon dioxide: responsible for 65% of overall climate warming effect (fossil fuel combustion and deforestation). CH4 = Methane: responsible for about 15% of warming effect (natural gas production, agriculture, melting permafrost). N2O = Nitrous oxide: responsible for 5% of climate warming effect (agriculture, industrial pollution). CFCs = Chloroflurocarbons: man-made chemicals responsible for about 15% of warming.  Science of Climate Change (IPCC Reports 2001, 2007, 2013, 2018 & 2021) “It is unequivocal that human influence has warmed the atmosphere, ocean and land. Widespread and rapid changes in the atmosphere, ocean, cryosphere and biosphere have occurred.” “Observed increases in well-mixed greenhouse gas (GHG) concentrations since around 1750 are unequivocally caused by human activities.” - (IPCC, 2021)  IPCC: Key Findings Global mean surface temperature was 1.09C higher in 2011-2020 than 1850-1900; Global emissions of CO2 primarily due to fossil fuel combustion and land use change; Emissions of CH4 are due to agriculture, leakage from fossil fuel extraction, and permafrost melting; N2O emissions are primarily from agriculture; Of cumulative CO2 emissions, about half have accumulated in the atmosphere and half have been absorbed in oceanic and terrestrial carbon sinks; CO2 concentrations in the atmosphere are higher than at any time in at least 2 million years; CH4 & N2O concentrations are higher than any time in at least 800,000 years… Keeling Curve: Atmospheric CO2 Levels  Effects of Global Warming: more extreme weather “Human-induced climate change is already affecting many weather and climate extremes in every region across the globe. Evidence of observed changes in extremes such as heatwaves, heavy precipitation, droughts, and tropical cyclones, and, in particular, their attribution to human influence, has strengthened…” - (IPCC, 2021) Record California Drought Linked to Climate Change, Stanford researchers say.  Unprecedented Wildfires: Canada, United States, Europe, etc. (2017-2023)  Effects of Global Warming, cont’d. Ecosystem bands shift northward: increased species extinctions anticipated; Tropical diseases and “pests” migrate northward * Malaria * Dengue fever * Zika virus * West Nile; Lyme disease * Agricultural and forestry pests (survive milder winters) -- e.g., mountain pine beetle  Effects of Global Warming, cont’d. Sea level rise due to thermal expansion of seawater and melting of glaciers and polar ice sheets; Coastal habitats threatened (coral reefs, mangroves, salt marshes, dunes, etc.). IPCC, 2013 Climate change will cause Alaskan village (Kivalina) to vanish under water within 10 years: Scientists (NY Daily News)  Key Points of Scientific Uncertainty Unanimous consensus amongst scientists that anthropogenic- caused global warming (AGW) is underway, but uncertainties remain: The degree to which at least some of the warming may reflect natural variation vs. anthropogenic cause, although scientists have largely sorted-out these different effects; Role of the deep ocean as both a heat and carbon sink; Role of increasing humidity and cloud formation: water vapor is a GHG, but clouds reflect sun (reduce greenhouse effect); Confounding effects of anthropogenic ‘global cooling’ due to SO2 emissions and other particulate aerosols… “… aerosols and their interactions with clouds have offset a substantial portion of global mean forcing from greenhouse gases… (and) … contribute the largest uncertainty to the total RF estimate” (IPCC, 2013)  Scientific Uncertainty, cont’d. Predictive value of science is typically the weakest link, yet this is what policy makers want to know: How fast will climate change and how will its effects play-out from region to region? The accuracy of climate models and predicted impacts remains uncertain, although evidence during the past decade tends to support their precision. Still, current models predict a change ranging from 1.5 – 4.5C over this century…that is a lot of uncertainty! Ability of animal and plant species to adapt to climate and associated changes; Ability of humans to adapt to climate and associated changes; Importance of positive and negative ‘feedbacks’ and related likelihood of catastrophic effects: worse case scenarios not likely, but not ruled-out either. IPCC 2021 Climate Change Science meets Global Warming Politics… Politics of Climate Change Skepticism Uncertainties about the science of climate change have been systematically exploited for political gain: Degree of measured global warming questioned by skeptics who cite highly selective, non-credible data sources; Non-credible theories (e.g., sunspot cycles) promoted to provide alternative explanations for global warming; Accuracy of CC models constantly questioned; Bogus arguments raised in order to create the impression among the public and policy makers that the basic science of CC remains unsettled.  Politics of CC Skepticism, cont’d. But we have seen this kind of thing before… Systematic effort by chemical industry to discredit emerging science of toxicology that pointed to risks associated with use of pesticides and other chemicals (1970s); Systematic attempt by tobacco industry to discredit science about the risks of smoking to human health (1960s-80s); But the effort to discredit climate science has been much larger and better coordinated. Who is behind it and why?... Exposing the climate change deniers…  Politics of CC Skepticism, cont’d. The Motivations: Economic: the fossil fuel industry is among the wealthiest industries in the world. Climate change regulations are a direct threat to their profitability; Ideological: Libertarian, anti-government ideas are widely-held, especially in the US; The Public ‘Educators’ & Lobbyists: Right-wing think-tanks: Americans for Prosperity, Heritage Foundation, Fraser Institute, etc.; Right-wing media (Fox News, etc.); U.S. Chamber of Commerce, Canadian Association of Petroleum Producers (CAPP);  Politics of CC Skepticism, cont’d. The Financiers (follow the money!): Exxon Mobile (see: exxonsecrets.org); Koch Industries (coal, oil & gas pipelines, etc.); The Politicians: U.S. Presidents G.W. Bush and Donald Trump; U.S. Republican Party: pledge to not support climate change regulations; Canadian P.M., Stephen Harper: “The Kyoto Protocol is a socialist scheme…”  Political Progress on Climate Change: Slow, but steady… 1979: First World Climate Conference (Geneva); 1992: UN-Rio Summit: Framework Convention on Climate Change (FCCC) signed by 163 countries; 1997: Kyoto Protocol signed; 2000-2010: European Union leads on climate action; 2005-2015: Some Canadian Provinces and US States move forward: B.C. carbon tax, CA GW Solutions Act; Ontario Green Energy Act; N.S, Sustainability Act, etc.; 2012-present: China invests massively in renewables;  Paris Climate Change Accord (2015) Unanimous agreement: 191 countries; Warming will be limited to no more than 2C (preferably 1.5C); EVERY nation has responsibility to reduce emissions; Nationally Determined Contributions (NDCs): all nations required to submit detailed emission reductions plans; Progress on emissions plans will be formally and transparently reviewed at subsequent international meetings on climate change; Relies heavily on peer-pressure and assumes national plans will ratchet-up over time;  Canadian Efforts centered around the Pan-Canadian Framework on Climate Change (2016-) First comprehensive, Canada-wide policy to set concrete emissions reduction targets and regulatory means to achieve them; Joint Federal-Provincial initiative with policies crafted to suit Provincial contexts; Carbon tax: Federal Greenhouse Gas Pollution Pricing Act (2018); Climate Change Accountability Act (2021). 2019/20: Global climate strikes…  Recent Political Developments 2019-20: Worldwide, youth-led climate strikes; 2020: Joe Biden elected as U.S. President: establishes climate change as #1 priority of U.S. government; 2021: U.S, Canada, U.K. & E.U. commit to strengthened emissions reductions targets; 2022: US passes the Inflation Reduction Act (IRA), a massive clean energy spending bill that triggers race to decarbonize industry, transportation, etc.; 2022-3: War in Ukraine prompts huge increase in clean energy spending in European Union.  Science and Environmental Problem-Solving: Challenges & Limitations Science is limited in what it can tell us about the world because the world is so varied and complex; Decision-makers care more about prediction than understanding, yet the predictive value of science is often weak; ‘Scientific objectivity’ often gets lost in decision- making, especially where controversial. One can find experts to support differing positions (e.g., NGO scientist vs. industry scientist); Scientific knowledge is often irrelevant and inaccessible to the needs of decision-makers;…  Science and Environmental Problem-Solving: Challenges & Limitations, cont’d. Scientific understanding, even when good, will often be subservient to economic and political priorities (e.g., reluctance to regulate greenhouse gas emissions); Environmental decisions are often made in the absence of sound scientific understanding; Environmental problems are inter-disciplinary, but research tends to be highly specialized. Environmental management is as much or more about managing people as it is about managing the environment!