It can be pretty overwhelming to think about the many adverse impacts that climate change will have on human health in the planet. However, the good news is we have two very strong principles that we can apply in order to reduce the impacts of climate change. We're going to explore those in this module. Looking at this graphic at the top, we know that greenhouse gas concentrations are being driven by anthropogenic activities. That's forcing climate change. Those concentrations lead to climate change. The changing climate leads to impacts, and those impacts lead to responses on our part as they must. In this graphic, you can see the red mitigation box is basically a feedback loop between our responses to climate change, and the greenhouse gas concentrations. In other words, we actually want to impact the concentrations themselves in order to medicate these changes to the climate. Here you can also see a feedback loop for the purple adaptation box, and this is basically a feedback loop between those impacts and our responses. Let's talk about some specific strategies that we can apply for both adaptation and mitigation purposes. Looking at the venn diagram here in purple on the left we see adaptation, and this would include things like changes in land use or relocation. If there are certain areas that are simply going to be uninhabitable due to climate change. We don't let people build there anymore or we relocate them to other areas. We could also think about continuity planning for emergency situations, and for businesses to maintain operations during a changing climate. We could upgrade or harden our buildings and infrastructure to make them more resistant or better able to withstand a changing climate. We could basically put into place residential programs that are designed to promote adaptive behaviors among our populations. We can and need to put into place health programs to support people's health during this changing climate. That's adaptation. If we switch over to the red in mitigation, we can think about things like energy conservation and efficiency. The less energy we use typically, the less greenhouse gases were going to emit. We could also think about renewable energy sources that don't create any greenhouse gasses. We need to focus on sustainable transportation and improved fuel efficiency again, to reduce the amount of fossil fuels we use, and reduce climate change impacts that way. We could also think about very specific solutions like capturing, and using some of the methane gas that escapes from landfills. We can also think about creating carbon sinks, basically areas where we can store carbon, so it's not getting into the environment and causing climate change. Again, at the center of this venn diagram, we see this green area which are activities that basically include both adaptation and mitigation. Things like sealing our buildings that can make them more resistant to climate change, but it also makes them more energy efficient. We can think about approaches like introducing green infrastructure, parks and other areas that can absorb maybe some of the fury of natural disasters and storms. We can think about conserving water and energy, we simply use less and we also absolutely need to think about smart growth planning our urban areas and our areas that are impacted by climate change in a way that's going to minimize those impacts. Let me talk about some specific examples of mitigation here and I want to focus on transportation emissions. These are a major source of greenhouse gases that are driving climate change. We know that transportation creates smog and soot, and there's health and also welfare impacts there, but it also creates greenhouse gases that are responsible for climate change. What transportation sources are we talking about? On the left here you can see maybe the sources that might come to mind immediately. Light duty or general passenger vehicles, heavy duty vehicles and trucks and motorcycles on roads. But on the right, we have a number of non-road sources too, things like airplanes and forklifts and other non-road diesel equipments, marine engines and ships, locomotives, your lawn and garden hardware that runs on gasoline and also recreation vehicles. All of those sources are emitting air pollution absolutely. What we want to focus on here is ways we can reduce those emissions to result in cleaner air and better health. Fortunately, we have lots of technological approaches available to us here. Things like catalytic converters on cars that can be used in combination with specific types of fuels to drastically lower emissions of certain types of contaminants. We could also think about improving our fuel standards to make our vehicles more fuel efficient, the less fuel we use, the less emissions. We can implement new engine technologies again, that make our engines operate cleaner and more efficient. Likewise, new transmission technologies can further improve our fuel efficiency. We can apply things like diesel filters to directly capture some of the particulate matter that's emitted from diesel engines. Were actively pursuing alternative vehicle technologies, new zero emission vehicles that at least don't have any greenhouse gas emissions from the tailpipe on the vehicle, because the vehicle doesn't have a tailpipe. Finally, we can think about simply doing better transportation planning, designing our transportation infrastructure to minimize the amount of time and energy it takes to get from point A to point B. I'd also like to highlight there are very much personal level approaches to climate change mitigation. In fact, our dietary choices have a direct impact on the greenhouse gas emissions that result from our diet. The graph on the left here is showing you the amount of greenhouse gases that are emitted by different types of meat, food sources and you can see cattle have an overwhelmingly larger greenhouse gas emissions associated with their production compared to other types of meat products. On the right here you can see greenhouse gas emissions from different types of diets. On the left side of this graph, you can see different amounts of meat that a person might consume per day, and the less meat you consume, the less greenhouse gas emissions result. We can see that if you eat no meat but you eat fish, your greenhouse gas emissions are further lowered. In fact, a vegetarian and a fish diet are quite similar in terms of climate change impact that in a vegan diet has by far the lowest greenhouse gas emissions. Let's switch from mitigation to adaptation. How can we adapt to a changing climate? Well, we could put into place things like flood defenses. The photo you see on the right here is an image of the Thames River barrier in the city of London. This is a barrier that's been purpose-built to basically close and prevent storm surge from an increasing both number and intensity of storms. Prevent that storm surge from traveling up and flooding the city of London. We could also think about hardening our structures that bright orange home you see here is a coastal home in a zone that's at risk of flooding. The home has actually been elevated on stilts so that if a flood does occur, the home itself is not damaged in the water passes safely under it. We could also think about changes in land use maybe we no longer allow people to build a home in this coastal zone because it's simply at too high a risk of storms or flooding. Finally, let me wrap up with a somewhat zany sounding idea, geoengineering. The notion behind geoengineering is that we actually purposely engineer the planet in ways that will minimize or reverse climate change. That's a big goal. Let me talk about some of the ideas that had been proposed already. In the upper left corner of this graphic, you can see increased reflectivity from low clouds. We might, for example, spray sea salt into clouds and make them wider and wider clouds tend to reflect more solar radiation, which prevents that solar radiation from being trapped in our atmosphere. We could also think about thinning high clouds. The notion here again is that we can manipulate the cloud layers above us in ways that are going to eliminate or reduce the amount of radiation they absorb. In fact, some folks have suggested we actually inject nano particles into the upper stratosphere, that's the upper right-hand corner here. Those nano particles would be engineered specifically to reflect solar radiation back out into space. A little closer down to earth, we can think about things in the ocean that we could do in the lower-left corner. We could increase the reflectivity of the oceans by, for example, trying to change the amount of carbon dioxide that gets absorbed into those oceans. We could do something called ocean fertilization, which is basically trying to improve the number and amount of plankton that exist in the ocean. With those plankton actually basically consuming carbon from the environment. We can think about biomass energy also with capture and storage. If we can run our homes in a way that we use biomass, but we also trap some of that carbon dioxide and store it in a carbon sink, that would reduce our greenhouse gas emissions. Maybe we engineer our crops in a way that they become more reflective. Or on the far-right, maybe we can make our deserts more reflective so they don't absorb as much solar radiation. Finally, we could think about a forestation, basically planting more trees. Trees are a very good way to absorb carbon dioxide out of the atmosphere, and as an added bonus, they then turn it into oxygen that we need to breathe. Hopefully, you get some sense here of the mitigation and adaptation approaches that we can take to try to minimize the impacts both on human health but also on the environment from climate change, and promote public health at the end of the day.
