The links below provide an outline of the material for this lesson. Be sure to carefully read through the entire lesson before returning to Canvas to submit your assignments.
Our goal this week is to explore the latest scientific consensus on the causes of global climate change and its social, economic, and environmental impacts. This week's materials will provide a broad overview of the current state of knowledge on these issues, and also bring together many of the topics from the semester - including biodiversity, environmental justice, and natural resource extraction - to consider possible ways forward to a sustainable future.
At the end of this week, you should be able to:
Let's dive in!
The Intergovernmental Panel on Climate Change (IPCC) is the leading international body for the assessment of climate change. It was established by the United Nations Environment Programme (UNEP) [3] and the World Meteorological Organization (WMO) [4] in 1988 to provide the world with a clear scientific view on the current state of knowledge in climate change and its potential environmental and socio-economic impacts. In the same year, the UN General Assembly endorsed the action by WMO and UNEP in jointly establishing the IPCC [5].
The IPCC is a scientific body under the auspices of the United Nations (UN). It reviews and assesses the most recent scientific, technical, and socio-economic information produced worldwide relevant to the understanding of climate change. Thousands of scientists from all over the world contribute to the work of the IPCC on a voluntary basis.
The IPCC is an intergovernmental body. It is open to all member countries of the United Nations (UN) and WMO. Currently 195 countries are members of the IPCC. Because of its scientific and intergovernmental nature, the IPCC embodies a unique opportunity to provide rigorous and balanced scientific information to decision makers. By endorsing the IPCC reports, governments acknowledge the authority of their scientific content.
The Working Group I contribution provides a comprehensive assessment of the physical science basis of climate change. The climate change report [2]includes a detailed assessment of climate change observations throughout the climate system; dedicated chapters on sea level change, biogeochemical cycles, clouds and aerosols, and regional climate phenomena; extensive information from models, including near-term and long-term climate projections; and a new comprehensive atlas of global and regional climate projections for 35 regions of the world.
NARRATOR: The scientific evidence is stronger than ever. Better and more observations, improved understanding of the climate system response, further development of climate models all point in the same direction. Human influence on the climate system is clear.
QIN DAHE: [SPEAKING CHINESE]
THOMAS STOCKER: We have looked at all the evidences that tell us how the climate has changed in the past and presently, took that evidence to ask ourselves how we understand the climate system, what the causes of these changes are, and then take that knowledge and climate model simulation to ask ourselves what possible futures are there.
NARRATOR: Many of these observed changes are unusual or unprecedented on timescales of decades to millennia. Ice cores contain an abundance of information about climate. Paleoclimate records show a closer link between CO2 concentration and temperature. These trends are seen in current observations. Each of the last three decades has been warmer than all preceding decade since 1850, and first decade of the 21st century has been the warmest.
DENNIS L. HARTMANN: Well, I think in AR5, we've done a much better job of expressing exactly how much different contributions, particular greenhouse gases, have contributed to global warming in the past and how they will contribute in the future. We're able to demonstrate that the CO2 concentration in the atmosphere has increased by 40% since pre-industrial times mostly as a result of human activities and that the levels of carbon dioxide in the atmosphere are higher than they've been for the last 800,000 years in Earth history.
NARRATOR: The effects of global warming are most evident in some of the coldest places on the planet. Ice sheets and glaciers worldwide are losing mass. Permafrost is thawing, and the snow and sea ice cover in the Arctic is decreasing.
JOSEFINO C. COMISO: We're getting a lot of signals from the cryosphere in terms of warming. The most visible signs of warming can be found in the Arctic.
NARRATOR: Arctic Sea ice extension has shown a downward trend since 1980. The downward trend is also observed at the Greenland ice sheet.
JOSEFINO C. COMISO: The amount of mass that's lost in Greenland is about six times as much as what was observed 10 years ago.
NARRATOR: The observed changes in the cryosphere have serious implications. With less snow and ice, more of the sun's energy is absorbed by the ocean and land surface. This is one of the powerful climate change feedbacks that influences the whole climate system. Based on multiple lines of independent evidence, it's now virtually certain that the ocean is warming.
MONIKA RHEIN: The warming of the ocean will continue even if we stop the atmospheric CO2 concentrations to increase because the timescale of the ocean circulation which connects the surface to the deep ocean is very large in the sort of hundreds and thousands of years.
NARRATOR: There are four major contributors to sea level rise-- ocean heat outtake, melting of glaciers, reduction of ice sheets, and changes in water storage on land. Improved scientific understanding has made scientists able to make a consistent sea level rise budget.
JOHN A. CHURCH: Over the 20th century as a whole, the dominant contributions are ocean thermal expansion and the contribution from the loss of mass from glaciers. Sea level has risen by about 19 centimeters by 1900 to 2010, and it's continuing to rise. We will have to adapt to sea level rise.
NARRATOR: Our understanding of the climate system relies on combining observations and studies from many different scientific disciplines. With the help of supercomputers, this knowledge can provide climate projections for the future.
RENO KNUTTI: Climate models play an absolutely crucial role in this assessment report. They are the only tools that allow us to say something quantitative about the future. Historically, climate prediction has started with predicting weather, the atmosphere, and we included the ocean. And now we're at the point where we include every component in the Earth system, including the carbon cycle and the chemistry. So that allows us to have a really comprehensive view of all the relevant processes for future climate change.
NARRATOR: Climate change projections require information about future emissions or concentrations of greenhouse gases, aerosols, and other anthropogenic drivers. A new set of scenarios was used to project the cumulative CO2 emissions in the future.
THOMAS STOCKER: Model simulations employing the RCP scenarios tell us we have a choice. We have a choice to live in a world in which climate change is limited to less than two degrees Celsius or in a world that is warmer than four degrees Celsius.
NARRATOR: Climate models employing the RCP scenarios provide policy relevant information on a regional level. For the first time, working group one has developed an atlas of global and regional climate projections, which allows decision makers to see how climate might change in their regions. This can facilitate more informed decisions on adaptation strategies.
THOMAS STOCKER: We have three key messages-- a warming in the climate system is unequivocal. That is based on the observations of the multiple lines of independent evidence. The second message is human influence on the climate system is clear.
This is resulting from the combination of model simulations with the observed climate change. The third message is that the continued greenhouse gas emissions cause further climate change and constitute multi-century commitment in the future. Therefore, we conclude limiting climate change requires substantial and sustained reductions in greenhouse gas emissions.
To prepare yourself for the quiz, please watch the video by clicking on the image above.
The 10th Session of Working Group II (WGII-10) was held from 25 to 29
March 2014 in Yokohama, Japan.
Penn State was represented in the negotiations over this report by Petra Tschakert [8], who now is a Professor in the School of Earth and Environment at the University of Western Australia.
The Working Group II contribution considers the vulnerability and exposure of human and natural systems, the observed impacts and future risks of climate change, and the potential for and limits to adaptation. The chapters of the report assess risks and opportunities for societies, economies, and ecosystems around the world.
PRESENTER: Climate change is the challenge of managing risks, risks for people and infrastructure, risks for ecosystems, risk for fresh-water resources and food production. Step to build resilient societies can reduce these risks. Adapting to climate change can benefit communities, economies, and the environment.
CHRIS FIELD: The role of working group 2 of the Intergovernmental Panel on Climate Change is to assess what's known and what's not known in the scientific body of literature about impacts of climate change-- what are the physical changes that have occurred and will occur in the future-- what's the vulnerability, who's susceptible to harm and why, and adaptation-- well, what can be done to cope as effectively as possible with the climate changes that can't be avoided.
[SPEAKING SPANISH]
PRESENTER: Substantial and wide-ranging impacts of climate change have occurred across the world. Climate change is already affecting ecosystems, human health, fresh water resources, and agriculture. Over the past few decades, yields of major agricultural crops have not increased as much as they would have without climate change. Climate change poses risks for food security in the future. Ongoing warming and acidification of coastal waters have impacts on marine ecosystems.
JOY PEREIRA: Climate change has affected both the land and ocean species. You find that species changing, moving places, migrating. And in the case of trees, you find a higher rate of mortality.
CHRIS FIELD: The main message from all of these observed impacts is that many features of ecosystems and the economy are very sensitive to changes in climate. And when we look forward to the possibility of changes in climate that are much larger than the ones we've already seen, the risk of much greater impacts is also very clear.
PRESENTER: The impacts of extreme climate events tell us a lot about current vulnerability and exposure of ecosystems and societies.
ANDY REISINGER: What they're observing is a significant adaptation deficit in both developing and developed countries. Society at large is actually more vulnerable and more exposed to climatic extremes even in the current climate than one might expect. And that tells us something about the challenge of moving forward into a changing climate where be have yet to catch up with where we're at now.
PRESENTER: Poverty can intensify the impacts from climate change.
PETRA TSCHAKERT: Living at the margins of society and being highly exposed, like living in the flood plain or being homeless, makes people vulnerable to climate change-- not the floods or a drought or heat stress per se. So it's about these inequalities that exist in every society, both in the north and the south, that make people vulnerable. And often they're associated to gender, to age, well-being, health, class, race, ethnicity, and whether or not people have access to resources a stake in decision making processes.
CHRIS FIELD: Risks from climate change really emerged from the overlap between three very different kinds of factors. One factor is hazard-- how much does the climate change, what is the extreme events. The second is exposure-- what kinds of assets are at risk, property, investments, economic values. And the third is vulnerability. What's the sensitivity to harm, the potential to be harm for people in ecosystems? And if they're going to be damages from climate change, risk, they really emerge from the overlap between these three-- the overlap between the climate hazard, the exposure, and the vulnerability. That's what produces climate-related risk.
Risk-- are we prepared for the challenges we face now? Are we prepared to deal with the challenges in the future? I'd like each of you to think about, not only climate change, but also changes in governments, in finance, in national security.
PRESENTER: It's important to consider regional and local settings to understand the risks associated with climate change.
DEBRA ROBERTS: When you look at the risk aspect of climate change, it almost seems that climate change is the only thing brings risk. But if you work and live in an African city, our day to day existence is about risks. So what climate change brings is another layer of risk, and the question is, how do we look at this new risk in relation to existing risks.
LEONARD NURSE: Risk is conditioned, for example, by people's worldview, what level of damage or loss that a community or a nation is willing to accept. And risk is also important from the point of view of the choices that you make. So a key aspect of climate risk management is making choices under conditions of uncertainty.
PRESENTER: Future greenhouse gas emissions and land use change will determine the magnitude of future climate change. Risks for people, societies, economies, and the environment increase with further warming. Mitigation can reduce risks. Adaptation to climate change is also important for reducing risks.
LEONARD NURSE: One of the key messages from the working group is that adaptation and mitigation are complimentary activities.
CHRIS FIELD: One of the real challenges we face is establishing the understanding that the benefits of adaptation and the benefits of mitigation play out on different time scales.
LEONARD NURSE: Sure.
PRESENTER: The effects of adaptation can be more near-term and immediate. But mitigation actions implemented early can make it easier to adapt more effectively in the long term.
CHRIS FIELD: Investments in mitigation in the short term really lead to an era of climate options in the long term.
[MUSIC PLAYING]
PRESENTER: Adaptation to climate change is starting to occur-- flood barriers and improved drainage reduce the risks from flooding in large cities. Farmers are managing their lands differently, for example, changing their planting times or using different varieties.
New climate-smart buildings makes cities more resilient. Green roofs decrease the risk of flooding during heavy rainfall and keep buildings naturally cooler during heat waves.
So what we have here is a new technology that's being implemented. It's effective, and it's attractive.
DEBRA ROBERTS: And I agree. I think the real challenge is this is an experiment in a resource rich environment. So the question is, how do we find something similar lessons that we can scale up in places in the global south.
The global south is already dealing with so many challenges. They can't afford for climate change adaptation to be a new agenda. So what we need to do is find ways of using existing resources, existing workstreams, and existing people to tackle this new challenge.
PRESENTER: Durban's most ambitious climate adaptation project is the reforestation in the [INAUDIBLE] landfill site. The project combines carbon sequestration and restoration of ecosystem services with community upliftment. The local community is paid to grow the trees, plant the trees, and manage the future forest.
[villager 1] The project helps the community to change their livelihoods and also to improve the environment that we are living in.
[villager 2] For them it's not only to come here and work and earn money, but to learn and go out to other communities and be like the ambassadors.
DEBRA ROBERTS: It's the fact that we can draw together quite simple things-- trees and people-- in a way that creates a bit more cohesive community, a cleaner community, and a more functional city. That's the exciting thing.
[Man]: There are a range of response options, both mitigation and adaptation, at our disposal to manage the risks associated with climate change. Now regardless of which option we want to pursue, there's a common set of ingredients we need to facilitate implementation. So we need resources. That might include knowledge. It might include finance. We need governance and institutional arrangements to facilitate coordination. And we need effective leadership from the top down and the bottom up.
CHRIS FIELD: In facing a future with climate change where there's uncertainty, we need to view it as a challenge in managing risks. The way I look at it is that adaptation in response to these risks, some of which are well-known and some of which are not, is trying to find a way to build a society that's more vibrant, more secure, richer, and fundamentally more resilient.
[Woman:] So then the question is, how are we going to achieve that.
CHRIS FIELD: The how involves a wide range of future steps that need to be taken at every level in society.
One of India’s leading physicists, Dr. Vandana Shiva is also a prolific author, world-renowned environmental activist, and eco-feminist whose work focuses on the fundamental connection between human rights and protection of the natural world. A fiery critic of globalization and the WTO, Shiva is a controversial crusader for biodiversity, women, and the world’s poorest and most populous nations.
In her book, Soil Not Oil, Vandana Shiva connects the dots between industrial agriculture and climate change. Shiva shows that a world beyond dependence on fossil fuels and globalization is both possible and necessary.
Condemning industrial agriculture as a recipe for ecological and economic disaster, Shiva’s champion is the small, independent farm: their greater productivity, their greater potential for social justice as they put more resources into the hands of the poor, and the biodiversity that is inherent to the traditional farming practiced in small-scale agriculture. What we need most in a time of changing climates and millions hungry, she argues, is sustainable, biologically diverse farms that are more resistant to disease, drought, and flood. In her trademark style, she draws solutions to our world’s most pressing problems on the head of a pin: “The solution to climate change,” she observes, “and the solution to poverty are the same.”
(Registered students can access a copy of this reading in Canvas)
This week we have learned about the transformations currently underway around the globe as a result of human-induced climate change, and about the future risks to humans and their environment. We have also learned about some possible ways forward to a more just and sustainable future.
All assignments will be submitted in Canvas, check the calendar in Canvas for specific due dates.
Links
[1] https://www.youtube.com/watch?v=6yiTZm0y1YA
[2] http://www.climatechange2013.org/
[3] http://www.ipcc.ch/docs/UNEP_GC-14_decision_IPCC_1987.pdf
[4] http://www.ipcc.ch/docs/WMO_resolution4_on_IPCC_1988.pdf
[5] http://www.ipcc.ch/docs/UNGA43-53.pdf
[6] https://www.youtube.com/watch?v=jMIFBJYpSgM
[7] http://ipcc-wg2.gov/AR5/
[8] http://www.see.uwa.edu.au/contact/staff?type=profile&dn=cn%3DPetra%20Tschakert%2Cou%3DSchool%20of%20Earth%20and%20Environment%2Cou%3DFaculty%20of%20Science%2Cou%3DFaculties%2Co%3DThe%20University%20of%20Western%20Australia
[9] http://www.navdanya.org/campaigns/soil-not-oil