Elizabeth May

Article / Updated 06-15-2023

The wildfires burning across Canada have become a global story. As of early June, more than 10 million acres have burned, and it could be Canada's worst wildfire season ever. The fires have led people to wonder, "does climate change cause wildfires? While it's uncertain whether climate change has directly caused these particular fires, scientists do believe that, overall, we are seeing more wildfires every year because of a warming planet. The increase in hot, dry weather means drier forests, grass, and undergrowth, ideal fodder for fire. Forest fires and wildfires around the world last longer and burn with more intensity than previously recorded. The area of land burned by wildfires has surged in the past 30 years across North America. The Intergovernmental Panel on Climate Change (IPCC) reports that a 1-degree Celsius rise (1.8 degrees Fahrenheit) in average temperatures has increased the length of the fire season in northern Asia by 30 percent. In Canada, we increasingly hear people refer to summer as “fire season.” Here we look closer at the consequences of wildfires, climate change, and the ways it leads to fires blazing out of control and what people can do to prevent them. The costs of wildfires and climate change These fires have serious consequences, not only for the environment and our health (air quality suffers), but also for infrastructure. Major wildfires in Australia, in 2020 displaced 3 billion animals, while intense fires devastated areas from California to Greece to British Columbia. The 2007 fires across the state of California destroyed 1,500 homes. As the IPCC expected, forest fires and wildfires have increased while temperatures continue to rise and some areas experience reduced rainfall. The first major economic hit to Canada from the climate crisis was the dramatic pine beetle outbreak in British Columbia. The pine beetle is an insect that has a special talent for turning a forest into firewood. Previously, pine beetles didn’t survive the winter. Due to warmer winters, the insect numbers hit catastrophic levels and wiped out an area of forest twice the size of Sweden. All that standing dead wood combined with rising temperatures to create a perfect storm for wildfires. Fires in 2017 and 2021 made breathing unsafe over a large area due to smoke, and very dramatically on July 1, 2021, in 15 minutes, burned the entire town of Lytton to the ground before the fire truck could get out of the station. In fact, because of both fire and increased insect damage, forests in Canada ceased to be a net sink (refer to Chapter 2) for carbon in the mid-1970s. Canada’s forests still hold millions of tons of carbon, but on an annual basis, these forests now give off more carbon than they suck in. Adding to this vicious cycle, forest fires pump carbon dioxide into the air when the wood burns and releases the gas. Recognizing how they start and how to prevent them When trees are tinder dry, it doesn’t take much to start a wildfire. Even dry grass can cause devastating fires as happened near Denver, Colorado, in late 2021. Successive years of drought create fuel for fires. When local practices don’t remove that fuel, the chances of fires increase. Communities and larger governments need to promote fire smarting to remove the fuel on the forest floor. Controlled burning as was practiced by indigenous people can help keep wildfires from burning too long or too hot and out of control. When conditions are perfect for fires, it doesn’t take much to cause a disaster. A carelessly tossed cigarette but, a spark from heavy equipment, and quite commonly a lightning strike can cause a massive fire. In the summer of 2021, with more than 1,600 significant forest fires across British Columbia, we learned a new word pyrocumulonimbus — clouds that are formed by fire and rise very high into the atmosphere. Often they carry burning materials from the original fire that can fall to earth far and ignite new fires.

Article / Updated 04-20-2023

Conversations about the cause of global warming typically focus on the big offenders — the worst industries, dirtiest factories, and scoff-law nations. There’s nothing wrong with that. But everyone plays a role in climate change. Each of us uses energy — specifically, fossil fuels — on a daily basis: Electricity: From the moment the alarm sounds in the morning until you shut off the computer or TV at night, you’re connected to an electrical grid, often fueled by coal or oil. Transportation: Everyone needs energy to move from here to there — a steady supply of gas for your car or diesel fuel for the bus you ride to work. Food: Most of humanity’s food travels great distances before it arrives in homes, a journey it undertakes thanks to greenhouse gas (GHG)-producing fuels. Typically, in talking about climate change, big business and government tend to point the finger at the individual. Asking citizens “What are you prepared to do?” even when it’s hard and expensive to make personal changes without a major structural shift further up the food chain, becomes an excuse for inaction by those with the real power to make change. The COVID pandemic gave a real-life lesson in how much the individual is really to blame. For all of 2020, citizens everywhere around the world drove a whole lot less and flew hardly at all. You would have thought that GHGs would have dropped and in a big way. They dropped — but only by 6.4 percent, according to Nature. And because of emissions in previous years, the concentration of GHGs in the atmosphere continued to rise, smashing through previous records to 412.5 parts per million (ppm) — more than at any time in more than 3 million years. Still, individual choices do matter. The most powerful individual change you can make is political by letting your elected officials know you demand they take the climate emergency seriously. And the personal choices you make are important. They send a signal. They keep your own sense of personal choice and personal power intact. How transportation impacts global warming About 24 percent of all GHG emissions come from moving people and goods, according to the World Resources Institute. In the United States, the proportion is higher; closer to one-third of emissions come from transportation — 29 percent. In Canada, it’s 25 percent. Almost all transportation — about 95 percent, according to the Intergovernmental Panel on Climate Change (IPCC) — runs on oil-based fuels, such as diesel and gas. This explains why transportation accounts for such a large portion of overall emissions (electrification of transport is rising fast around the world, but it’s still only about 2.2 percent of all vehicles). Cars and diesel trucks are the top two offenders, but ships, airplanes, trains, and buses play a part, too. We discuss the culprits of driving and flying in the following sections. The figure below shows the breakdown of how each mode of transportation contributes to GHG emissions. Driving emissions Whether you need to run errands or drive the kids to soccer practice, cars, minivans, and SUVs are useful and often perceived as necessary. Most households in industrialized countries own at least one car because most cities and housing developments are built around road infrastructure — making it difficult to survive without one. However, that internal combustion engine now has serious competition — hybrid cars that generate energy to a battery to reduce fuel use and electronic vehicles (EVs), vehicles that run 100 percent on electricity. These technologies promise to make the internal combustion obsolete, just as that technology disrupted the horse and buggy. In November 2021, Hertz, a major U.S. car rental company, placed an order for 100,000 Tesla EVs — that’s how fast things are changing. Despite the pandemic, global sales of EVs increased by 43 percent in 2020. Still, even as sales of EVs and hybrids ramp up, in 2020 only 1 in 250 cars on the road is electric. The majority of people in the developing world still don’t have access to a personal vehicle — but that’s quickly changing. China is soaring ahead in private car ownership, which jumped from 45 million cars in 2009 to more than 225 million in 2019! Total EV sales in China were 1.3 million, an increase of 8 percent compared to 2019. The 2019 sales of EVs in China amounted to 41 percent of all EVs sold worldwide. Flying emissions Planes burn fuel similar to kerosene, which gives off more emissions than the gasoline in your family car. The 2018 IPCC special report on 1.5 degrees found that aviation has grown to 14 percent of transport sector global carbon dioxide emissions. Not only does flying emit a lot of GHGs, it emits them in the atmosphere in a more damaging way. The warming impact of the exhaust from air travel is far worse than the same volume of GHGs emitted on the ground. People made about 38.9 billion flights in 2019, and that dropped to less than 17 billion in 2020 due to the COVID pandemic. Still, it’s shocking that in 2007, globally, there were 4 billion individual plane trips for business or pleasure. And, even though flights dropped dramatically in 2020, they have started rising once again. The people of China are flying more and exploring their own country by air and rail. They’ve also increased what is called outbound tourism — that is Chinese tourists exploring other countries. In 2003, 20 million tourists from China explored the world. By 2019, that figure was up to 155 million! China now tops the charts for outbound tourism. Concern about the climate crisis is leading some countries to reduce flying. Impressively, the French government decided post-COVID that no domestic flights would be allowed where train travel was available. Increasingly, climate-aware travelers work to eliminate air travel altogether. The pandemic allowed many organizations to experience meetings — big and small — using online video technologies. The cost of flights and the wasted time traveling have likely made a permanent change in how employers see the practicality of video conferencing. This could increase the trend to staying home and avoiding flights wherever you can. If you have to fly, buying carbon offsets is a worthwhile option. Energy uses around the house In Canada and the United States, the floor space of the average home has continued to grow while family size is shrinking. House size has real implications for the climate crisis. The bigger the home, the more energy required to heat, cool, and light it. Fewer people are occupying — and heating and cooling — more space. When it comes to energy use in your home, you can think about it in two ways: Direct energy: This term refers to the energy you use, which comes from gas or fuel oil that you consume directly — such as the oil-fed heaters or propane gas stoves you may have in your home. Indirect energy: This term refers to how some other energy — oil, hydroelectric, wind, or nuclear power — is used to produce the direct energy. For example, natural gas is used to heat the oil sands enough so that the otherwise solid bitumen flows and can be extracted. How your electricity is produced affects your individual GHG emissions. The energy that people use in their homes accounts for about 25 percent of GHG emissions around the world. Most of the fossil fuel energy you use directly goes toward heating your home. You use most of your electricity to power your lighting and appliances. See the figure below for a complete breakdown of the percentages of GHG emissions produced from heating, lighting, and other energy uses. Your energy use may be very different than the average home. For example, you may not have an air conditioner. When talking about climate change, scientists mean changes to the global climate systems. But people can also talk about “climate control” in their homes. Modern air conditioning can make the indoors feel like winter in a sweltering summer. Controlling the climate in your home can also impact the global climate system. Controlling the climate in your home Homes in the United States create 150 million metric tons of carbon dioxide every year from heating and cooling alone for 333 million people, according to the U.S. Department of Energy. That’s a full 2020 percent of U.S. GHG emissions. Check out the following sections for how heating and cooling your home plays a role in global warming. Heating Heating takes either direct energy or electricity, depending on whether you have an oil or gas furnace or electrical baseboard heaters. Other types of home heating, such as wood stoves or gas fireplaces, also create emissions. The U.N Food and Agricultural Organization notes that burning wood for home heating (and in some countries, cooking, as well) accounts for about 6 percent of energy use in the world. Burning wood adds to GHG emissions both through the carbon dioxide released during burning and through deforestation. Older furnaces emit more GHG than newer models. These old clunkers guzzle fossil fuels, but unfortunately, many homeowners cling to them, worried about the expense of buying a new unit. In reality, these homeowners can save money if they buy a new energy-efficient furnace, which would save them significantly on energy costs — and be less costly to the planet, too. Cooling Electricity used to be used only for keeping the lights on. Now, it’s what keeps people cool all summer long. In fact, the largest share of home electricity use now goes directly to air conditioning. And in places such as south central Canada, the greater share of power demand has recently shifted from winter to summer. With more 86 degrees F (30 degrees C) days every summer — thanks to global warming — the demand for air conditioning goes up annually. Only industrialized countries used air conditioning, for the most part, until now. Recent news reports show that sales of home air conditioners have tripled in the last ten years in China. As countries such as China and India move to catch up to industrialized countries, residents are starting to widely use luxuries such as air conditioning. Add warming temperatures into the mix, and you can see a growing air-conditioning trend and a growing demand for electricity to meet that desire. Traditionally, most Europeans never considered air conditioning. But because killer heatwaves have ravaged Europe in recent years, this perspective is changing. For example, the U.K. had to consider new labor laws — in the past, laws ensured a legal minimum temperature so workers could stay warm enough. Because of intense summer heat, they’ve also had to consider legal maximum temperatures! Perhaps the most surprising area to need air conditioning is in Canada’s far north. Buildings in the Northwest Territories and the Yukon are now being built with air conditioning. The average high temperature in the summer in those territories ranges from 70 to 80 degrees F (in the 20s C), but has been warming up recently and has reached the 90s F (about 30 degrees C). Your food choices and global warming Like a warm home in freezing weather, food is a necessity, not a luxury. But sadly, when people sought to make food more accessible and more convenient and to offer a greater variety, they often did so without considering the environmental toll their innovations might have. Much of the food that people buy at the grocery store uses a lot of energy to get there — and creates a lot of GHG emissions as a result. Here are some of the key offenders: Frozen food: Whether you’re talking refrigerated or frozen, these foods burn energy when they’re made, while they’re being transported, and even when they’re sitting in a freezer or cooler in the grocery store (or in your home). The most-energy-used-per-serving prize goes to freeze-dried coffee. Processed and packaged food: Moving these foods through the production line takes energy, as does making the packaging (not to mention the emissions that come from all that packaging when it ends up in a landfill). Food from afar: Elizabeth never even saw a kiwi until she was about 18 years old. Her daughter started asking for them for her school lunch in first grade. You may enjoy strawberries and mangoes in the dead of winter, when you can’t pick fresh fruit right in your backyard, but moving exotic fruits and veggies around the world by plane, ship, and truck has a real cost in energy. Could people afford them if companies factored in the cost to the climate? And why should your apple be more well-traveled than you? Meat products: Feeding livestock takes an average of 10 pounds of grain — grain that plays a large role in agricultural emissions — to produce 1 pound of meat. Also, when people eat more meat, more land is needed to raise livestock, which often means clearing forests and losing trees that breathe in our carbon dioxide.

Article / Updated 04-04-2023

The rash of tornadoes that came in early spring 2023, devastating parts of the U.S. South and Midwest, no doubt had many people thinking about how climate change is affecting the weather. Tornadoes seem to be happening earlier in the season than ever, and in larger numbers. These violent storms also seem to be trending toward larger in size. Looking back to December 2021, a season not typical for tornadoes, northeast Arkansas, Tennessee, and western Kentucky were hit with tornadoes three-quarters of a mile wide with wind speeds that peaked between 158 and 206 miles per hour. Still, the connection between more severe and unexpected tornadoes and climate change isn’t linked with high confidence — yet. More major weather disasters Major natural disasters have always happened. Storms, hurricanes, floods, and droughts are all part of the planet’s natural weather and climate system. But, increasingly, natural disasters aren’t so natural. Human activity — burning fossil fuels and removing forest cover — has thrown the carbon balance out of whack. Greenhouse gases (GHGs) that civilization pumps into the atmosphere are driving increasingly dangerous weather. Earth is experiencing more droughts, floods, more intense hurricanes, forest fires and wildfires, heavier rainfalls, rising sea levels, slowing ocean currents, and more severe winter storms and major heatwaves. Warming oceans help fuel hurricanes Global warming is heating up Earth’s oceans. In fact, the Intergovernmental Panel on Climate Change (IPCC) reports that oceans have absorbed more than 90 percent of the heat from global warming. Hurricanes are now occurring in the top half of the northern hemisphere, such as Canada, because of these warmer ocean temperatures, particularly at the surface. Historically, colder ocean surface temperatures in the north slowed down hurricanes, turning them into powerful, but nowhere near as destructive, tropical storms. Now, however, the water’s warmer temperatures don’t impede storms. In fact, warming up surface water is like revving the hurricane’s engine. The number of tropical storms and hurricanes hasn’t increased. In fact, that number has stayed fairly uniform over the past 50 years, the IPCC reports. The intensity of tropical storms and hurricanes, however, has increased. Scientists have confirmed that hurricanes (also called cyclones and typhoons) have grown in strength and destructive force, while also growing in the geographical areas subject to these intense storms, moving closer to the poles. Extreme weather events from floods, to droughts, heatwaves, wildfires, and hurricanes are confirmed in the 2021 IPCC report and linked with high confidence to global warming. The first ever hurricanes to reach as far north as Canada were in 2003 in Halifax on the east coast (2003’s Hurricane Juan was the first full-force tropical hurricane ever to hit Atlantic Canada) and in 2006 in Vancouver on the west. Bigger storms, more damage These bigger storms and hurricanes bring rougher coastal storms, bigger storm surges, higher water levels, taller waves, more storm damage, and flooding. Scientists also see an increased tendency of these storms that stall over one area, such as Harvey in 2017, Florence in 2018, and Dorian in 2019. Some storm-protection barriers may not be strong enough to protect against the hurricanes that are coming, and some cities might need to reevaluate their protection. (Think New Orleans!) For the first time, the IPCC's 2021 report confirmed a risk (at low probability) that the excess carbon dioxide that people put into the air could disrupt the carbon cycle and turn the planet’s life-support system into a vicious cycle. Rainfall (or lack thereof) Changes in temperature are altering evaporation and precipitation patterns, which means more rain in some places and less in others. The IPCC says these changes also mean more intense dry spells and rainstorms overall, with high-latitude areas in Europe, Russia, and Canada taking the hardest drenching. The IPCC reports that inland mid-latitude regions — such as central Canada and inland Europe and Asia — are generally most at risk from more frequent and harsher droughts than what those areas currently experience. Although not in those regions, the land along the Mediterranean in Europe may also experience increased droughts. Droughts and high temperatures put major stress on forests and grasslands; dry, parched vegetation is a fire waiting to happen. The soil suffers, too. Dried-out soil can release into the air the carbon that it used to store. Drought is hard on people and animals because all living things depend on water. Global warming is also causing deserts around the world to expand. In Africa, the Sahara is getting bigger, while in China the Gobi Desert’s growth is a threat. In both places, countries are trying to arrest the increased desertification with green walls of tree planting. The Great Green Wall in China started with tree planting in the 1970s with billions of trees planted. Although it hasn’t been entirely successful, African nations are trying to learn from mistakes in China, such as planting in all one species, and hold back the Sahara with its own Green Wall. The IPCC reports that the duo of natural warming and human-caused warming has caused the number of dry areas around the world to double since the 1970s. More rain, rising seas lead to flooding Three climate change consequences lead to flooding: Rising sea levels Quicker-melting snow and glaciers More intense rainfall The IPCC expects that the rising sea levels and harsher rainstorms will increase the number of floods in many places, including both flash floods (floods that happen very suddenly, often because of heavy rainfall and/or the ground is so dry it can’t quickly absorb the rain) and large-scale floods (floods that stick around for a while, caused either by prolonged rainfall or water that can’t drain away easily). Climate change scenarios typically predict that average annual precipitation will remain nearly constant, but that areas will experience long periods of drought followed by an enormous volume of rain. This happened in California from early January to mid-March 2023, when heavy rain caused floods in large areas of the state. There was widespread property damage and at least 22 fatalities. Another example of flooding after drought occurred in China in summer of 2021, when as much rain fell in three days as usually falls in a year. That nation’s annual precipitation fell within days on the dry and desiccated lands. Three hundred people died. In the same summer of climate emergencies, torrential rains caused huge floods in Germany, Belgium and the Netherlands, killing 200 people. The most likely areas to experience more flooding are high-latitude countries, such as the United Kingdom.

Cheat Sheet / Updated 03-08-2022

This Cheat Sheet describes how and why greenhouse gases are formed, investigates some important global warming terms, uncovers the negative impacts of climate change, and offers solutions you can implement in your everyday life to alleviate rising greenhouse gas emissions. Although climate change is connected to ugly futures, melting icecaps, rising sea levels, soaring temperatures, worsening hurricanes and monsoons, and the list goes on, it’s also a link to a better future. Climate change is opening doors for the development of new types of fuels, leading the shift to reliable energy sources, and creating a vision of a greener tomorrow.

Cheat Sheet / Updated 02-16-2022

Global warming is already changing the environment, the economy, and people’s ways of living. The changes aren’t over, either, and the more that changes around the world, the more critical it is to understand this complex and important issue. The following describes how and why greenhouse gases are formed, investigates some important global warming terms, uncovers the negative impacts of climate change, and offers solutions you can implement in your everyday life to alleviate rising greenhouse gas emissions. Although global warming is connected to scary scenarios featuring soaring temperatures and worsening hurricanes and monsoons, it’s also a link to a better future. Global warming is opening doors for the development of new types of fuels, leading the shift to reliable energy sources, and creating a vision of a greener tomorrow.

Article / Updated 03-26-2016

What you can do to help reduce your carbon footprint depends on where you live, the resources you have, and how much time you can give. If you want to do something about global warming, however, then simple changes can have a big impact. Here are some straightforward solutions that you can implement right away: Eat less (or no) meat. Going vegetarian has the same impact on reducing greenhouse gas emissions as if you trade in a regular car for a hybrid. The process of making a pound of commercial meat uses ten times more energy than making a pound of beans or grains. * Hook your home up to clean energy. If you can’t afford to install solar panels or wind turbines on your roof, you can tap into an independent clean energy supplier. Let them build the wind turbine, and you reap the benefits. This step reduces your own emissions and helps build the renewable energy industry. Insulate your house. The average home has the equivalent of a basketball-sized hole in the side of its wall. That’s how much heating and cooling you can keep from escaping if you properly insulate your home’s ceilings, walls, windows, and doors. Travel smart. Reducing the number of flights you take in a year has a huge impact. One long-haul flight can be enough to double your impact on climate change, so think twice before taking that long trip. Whenever possible, take the train or bus. Minimize your driving by carpooling, walking, biking, or taking public transit. Use only the energy you need. Develop energy saving habits — turn off the lights and TV when you leave the room, and turn down your thermostats when the house is empty in winter, and up in summer. Choose low-energy technologies by looking for the ENERGY STAR or Energy Savings logos on all appliances, electronics, computers, and more. These qualification standards highlight products that use the least energy.

Article / Updated 03-26-2016

The phrase “global warming” hasn’t been around long, but climate change, as it’s also known, is nothing new. In fact, it has been a constant throughout history. Earth’s climate today is very different from what it was 2 million years ago, let alone 10,000 years ago. Here are the key terms that are crucial to understanding global warming: Carbon cycle: The natural system that, ideally, creates a balance between carbon emitters (such as humans) and carbon absorbers (such as trees), so the atmosphere doesn’t contain an increasing concentration of carbon dioxide. (Concentrations of carbon dioxide in the atmosphere are expressed as parts per million, or ppm.) Carbon sinks: Anything that absorbs carbon dioxide from the atmosphere and stores carbon. The ocean, trees, and soil are all carbon sinks. Fossil fuels: Fuels, such as oil and coal, that are made from the fossils of old plants, which have taken hundreds of thousands of years to form underground. Intergovernmental Panel on Climate Change (IPCC): An international body of the United Nations, composed of over 2,000 scientific experts. The IPCC compiles peer-reviewed climate science to create an objective source of climate information. Kyoto Protocol: The international agreement under the United Nations to reduce global greenhouse gas emissions from industrialized countries by 5.2 percent below 1990 levels by the year 2012. The Protocol is ratified by 177 countries. Renewable energy: A continual source of energy, such as energy from the sun, wind, flowing water, heat from the Earth, or movement of the tides.

Article / Updated 03-26-2016

Planet Earth is warm enough to sustain life thanks to gases in the planet’s atmosphere that hold heat. These gases are called greenhouse gases because they act just like a greenhouse — trapping the heat inside the planet’s atmosphere, making the average temperature on Earth 59 degrees Fahrenheit (15 degrees Celsius). Humans have increased the amount of greenhouse gases in the atmosphere by about 35 percent. The more greenhouse gases in the atmosphere, the warmer the average temperature gets. The main greenhouse gases The two major greenhouse gases both occur naturally and can be increased due to human activity. Carbon dioxide (CO2): Responsible for 63 percent of global warming over time, and 91 percent in the last 5 years, this gas is produced from burning fossil fuels, such as coal and oil. It also occurs naturally as it flows in a cycle between oceans, soil, plants and animals. Methane (CH4): Responsible for 19 percent of global warming, this gas is produced by rotting garbage and wastewater, gas from livestock, and rice crops. Swamps and anything that decomposes without air naturally creates methane. Two main sources of greenhouse gases Energy use: Humans derive energy from burning fossil fuels, which releases almost three quarters of all human-produced greenhouse gases into the atmosphere. Half of all fossil fuels are burned to provide electricity and heat; the next big users of fossil fuels are manufacturing and transportation. Land use: How humans remove forests and use land contributes over one quarter of all human-produced greenhouse gases to the atmosphere. Trees absorb carbon dioxide from the atmosphere, so logging and clearing forest land for agriculture and development means more carbon dioxide stays in the air.

Article / Updated 03-26-2016

The impact of global warming will increase in the coming years, but the degree of change will vary greatly, depending on where you live and depending on how rapidly nations around the world reduce greenhouse emissions. No matter where you live, though, the unchecked impacts of climate change are potentially catastrophic in the long-term. It affects people: Depending on their location, people may be affected by disease, rising sea levels, drought, or major storms. The impact of these effects will be greatest on those with the least financial resources to adapt to or recover from the effects. It causes extreme weather: While the atmosphere warms, the climate is changing, and so is the weather. More frequent and more intense storms, flooding, droughts, heat waves, and even extreme snowfalls are all part of the changes. It increases extinctions: Changing climates mean that some environments may no longer be hospitable for certain plants or animals, which will need to relocate to survive. Some species, such as polar bears, have nowhere to go. Extinction is a possibility for many species of animals and plants, which may be unable to adapt to their environment at the same speed at which the climate is changing it. It melts ice at the poles: The Arctic ice is melting so rapidly that within a few years the North Pole will be ice covered only seasonally. This has a dramatic impact on the planet’s climate: Polar ice reflects sunlight and deflects heat; when it melts, more of that heat stays in the atmosphere. The melting of the Greenland and Western Antarctic Ice Sheets threatens an extreme rise in sea levels. It warms oceans: While the oceans warm, water is expanding and causing sea levels to rise. Warmer waters are killing coral reefs and krill — essential to supporting the sea food web.