Our website uses cookies to understand content and feature usage to drive site improvements over time. To learn more, review our Terms of Use and Privacy Policy.
Grand Challenge 5 How We Keep Cool and Stay Warm
Grand Challenge 5 How We Keep Cool and Stay Warm
How do the ways we keep cool and stay warm contribute to climate change? Discover what we can do to cool ourselves and keep warm while reducing carbon emissions.
As this video progresses, key ideas will be introduced to invoke discussion.
Think about the following questions as you watch the video
How is Grand Challenge 5: How We Keep Cool and Stay Warm one big feedback loop, meaning its effects ultimately become its main driver?
How do air conditioners and heating methods produce carbon emissions?
Why is demand for air conditioners and heaters expected to rise in the future?
What are the Solutions for the How We Keep Cool and Stay Warm Grand Challenge?
What are heat pumps? Why are they significant to reducing emissions from heating and cooling?
Describe one obstacle to the widespread adoption of heat pumps.
: Are you comfortable? Are the temperature and humidity in your room just right?
: I have a very specific comfort band. If the air conditioning is set above 70 in the summer, I am
: burning up. And in the winter, I start shivering if the heat dips below 72. If you're comfortable,
: you're lucky. Climate change is making extreme heat and extreme cold events more common all
: around the world. And a lot of people lack access to sufficient heating and cooling.
: But, I have some good news... And some bad news... Unfortunately, the good news is also the bad news.
: As long as global poverty rates decrease, more people will have access to technologies like
: air conditioning. That's a good thing. Those people will live more comfortably
: and can escape extreme heat events. But, it's also a problem; the methods we use to heat and
: cool our buildings are a significant contributor to greenhouse gas emissions. The very thing we're
: doing to survive extreme temperatures are making those temperatures worse and more frequent.
: Let's start with the numbers: keeping cool and staying warm accounts for about seven
: percent of the 51 billion tons of carbon emissions that humans produce
: every year. Some of that comes from the energy we use to power air conditioners.
: Some comes from leaked refrigerants that air conditioners use to make our houses cold.
: Some come directly from fuels we burn to heat our homes, like gas and wood in fireplaces. Now, seven
: percent might seem small compared to other sources of greenhouse gas, but we have to consider every
: source of emissions if we want to get to net zero. And heating and cooling are set to become more
: important in the future. As the global climate gets more variable, parts of the world that
: never needed air conditioning or heating before will become desperate for them. As a result,
: global demand for cooling is expected to triple by 2050. When that happens, air conditioning
: alone will consume as much electricity as all of China and India combined do today.
: But, there's some good news in this Grand Challenge: we already have the technology to
: make our heating and cooling much cleaner. Getting started on solving this Grand Challenge is mostly
: about educating the public, and fixing public policies. We still need innovations (of course)
: and because so many of our clean heating and cooling solutions run on electricity,
: we'll need to decarbonize our electricity generation.
: But, getting to zero in this Grand Challenge is within reach.
: We call most of the technologies we use to warm and cool our houses "HVAC", for "Heating",
: "Ventilation", and "Air conditioning". I know... sounds super boring, but
: it's actually some pretty cool technology. Anyway, we're going to focus on HVAC in this
: video. But these technologies are just one of the pathways you can explore as you seek solutions to
: the Grand Challenge of How We Keep Cool and Stay Warm. So, let's briefly describe some others.
: If you watched the video for Grand Challenge Number 2: How We Make Things,
: then you know that humans are going to have to build a lot more buildings in the next 30 years.
: We need to make sure those new buildings are designed with zero emissions in mind.
: We can design buildings to be better at keeping us cool and warm.
: For example, passive solar construction uses extra insulation and heat from the Sun to
: keep buildings cool in the summer and warm in the winter. We can also update old buildings
: through a process called "weatherization" that replaces or improves walls, windows, and frames
: to make buildings less... leaky. That means they lose less heat or coolness to the air outside.
: We can also replace fossil fuels with somewhat cleaner biofuels. Unlike fossil fuels, biofuels
: emit carbon that has been recently captured by plants. This is a small but important difference.
: Fossil fuels release carbon that has been stored underground for millions of years, so burning them
: adds carbon that hasn't been in our atmosphere for ages. But by using biofuels, we capture
: carbon already in our atmosphere by growing plants and then return it when the biofuels are burned.
: But, let's get back to HVAC. Like I said earlier, the good news is that the HVAC technology we need
: already exists. Engineers have developed much more efficient units in the last few years.
: Some of these are heat pumps, which also make great air conditioners.
: Confused? You're not alone. A lot of people don't understand heat pumps. And yet,
: more than 99 percent of households in the United States already contain at least one—we just call
: it by a different name: the refrigerator! Like your refrigerator, heat pumps use coolants and
: loops of pipe to absorb heat from one place and move it to another. So, in the winter, they absorb
: heat from the air outside and move it inside. They can do this even in freezing temperatures.
: In the summer, heat pumps reverse this process to move heat out of your house.
: Heat pumps are kind of like the electric vehicles of HVAC. If we can power them with
: clean electricity, they can replace old gas and oil furnaces, and inefficient air conditioners
: with a zero carbon option. And we already have the technology in hand. But, there's a big difference:
: while electric vehicles are more expensive than gas-powered cars and have a high Green Premium,
: heat pumps can actually have a negative Green Premium, depending on where you live.
: That means it's cheaper to install a new heat pump,
: than to install a new natural gas furnace and electric AC—so why don't we all have one?
: Well, that brings us to the bad news: we have this technology readily available,
: but we aren't using it. Only 11 percent of homes in the United States have a heat pump.
: The biggest problem is that our government policies are outdated. Since the 1970s,
: government regulations have focused on efficiency rather than emissions. And until recently,
: natural gas furnaces and appliances were much more efficient than the old electric models.
: The other part of the problem is that consumers just don't have the information they need.
: For example, when buying a new AC unit, people often choose the cheaper option,
: not knowing that it's going to cost them more in the long run. The typical AC unit sold today is
: only half as efficient as what's widely available, and only a third is efficient as the best models.
: Unfortunately, there's another problem with HVAC systems:
: they contain refrigerants known as, "F-gases", because they contain fluorine.
: F-gases leak out little by little over time and they are powerful contributors to climate change.
: In fact, over the course of a century, they caused thousands of times more warming than an
: equivalent amount of carbon dioxide. We're going to need innovations that either replace F-gases,
: use them more efficiently, or prevent them from leaking. These, and other innovations,
: are all within reach. And remember, the great thing about cooling and heating is that a lot
: of the innovations we need already exist. We just need the policies and practices to support them.
: So, what can you do? The first thing you should do is look around you to figure out
: what's appropriate for your community. What kind of heating and cooling do homes around you use?
: What about your school and public buildings? Is natural gas really cheap where you live?
: Do a lot of people have wood stoves? Does your state offer tax incentives for heat pumps?
: What's the weather like in your town? If it's hot, cooling is probably a priority. But if you live in
: Northern Michigan, maybe you'll want to pay more attention to staying warm. You can also make a
: big difference by writing to local officials to include higher standards for AC efficiency
: and building codes. You can raise awareness at your school and to homeowners in your community
: about the benefits and lower costs offered by heat pumps. And in the long term, you might
: choose a course of study, like architecture or mechanical engineering, that would allow