The consequences of global warming are immense. Glaciers and ice sheets are melting and sea levels are rising as oceans are warming and expanding. Extreme weather events like torrential rain, floods, wildfires, hurricanes and droughts are becoming more frequent and more powerful. We are experiencing a destruction of both coral reefs and forests. We are watching the extinction of animal and marine life. As our environment changes in unpredictable ways the consequences are and will disrupt our health, our food supplies, our economics, and our safety.

 = The most basic and urgent information


CREDIT: Felipe Galindo

Q: Is it too late to prevent climate change?

A: Unfortunately, humans have already committed to a continuation of the changes we have seen over the past decades, such as the extreme weather and rising seas, because of the amount of carbon dioxide already in the atmosphere. It is estimated that if we stopped emitting all greenhouse gases, it would take 40 years for the temperature to stabilize with the average surface temperature rising 0.6 degrees Celsius over this time.

Q: How is global warming linked to extreme weather?

A: The impacts of global warming are being felt across the globe. The earth’s rising temperatures are fueling longer and hotter heat waves, more frequent droughts, heavier rainfall, and more powerful hurricanes. The earth’s ocean temperatures are getting warmer, too—which means that tropical storms can pick up more energy. So global warming could turn, say, a category 3 storm into a more dangerous category 4 storm. Extreme heat waves have also caused tens of thousands of deaths around the world in recent years. And in an alarming sign of events to come, Antarctica has been losing about 134 billion metric tons of ice per year since 2002. This rate could speed up if we keep burning fossil fuels at our current pace, some experts say, causing sea levels to rise several meters over the next 50 to 150 years. More at NRDC

Q: What are the other effects of global warming?

A: Each year, scientists learn more about the consequences of global warming, and many agree that environmental, economic, and health consequences are likely to occur if current trends continue. Here’s just a smattering of what we can look forward to:

  • Melting glaciers, early snowmelt, and severe droughts will cause more dramatic water shortages and increase the risk of wildfires in the American West.
  • Rising sea levels will lead to coastal flooding on the Eastern Seaboard, especially in Florida and Tidewater Virginia, and in other areas such as the Gulf of Mexico. This flooding will be most acute during storm surge events associated with hurricanes and other storms.
  • Forests, farms, and cities will face troublesome new pests, heat waves, heavy downpours, and increased flooding. All those factors will damage or destroy agriculture and fisheries.
  • Disruption of habitats such as coral reefs and Alpine meadows could drive many plant and animal species to extinction.

Allergies, asthma, and infectious disease outbreaks will become more common due to increased growth of pollen-producing ragweed, higher levels of air pollution, and the spread of conditions favorable to pathogens and mosquitoes. More at NRDC

Q: How will climate change impact water resources?

A: Climate change will be responsible for changing patterns of water availability, and shrinking glaciers and changing patterns of precipitation will increase the likelihood of drought and flood. If climate change is the shark, then water is its teeth and it is an issue on which businesses need far greater levels of awareness and understanding. More at Water Footprint Calculator

Q: If fossil fuel use continues at this pace, what are the consequences to the oceans?

A: “The world’s oceans and cryosphere have been taking the heat for climate change for decades,” said Ko Barrett, vice chair of the United Nations’ Intergovernmental Panel on Climate Change (IPCC), which produced the report on climate change’s impact on the oceans and cryosphere. “The consequences for nature and humanity are sweeping and severe.” Just how severe the impacts will become—whether sea level rise stops at 1 to 2 feet by 2100 or continues to rise as high as 3.5 feet; whether the planet sees 20 times more marine heat waves or 50 times more—depends on how, and how quickly, humanity responds to the crisis, the report found. More at InsideClimate News

Q: How will climate change affect major crops?

A: Crops like wheat, peaches, coffee, corn, and almonds will see the impact:

  • Wheat will suffer from hotter temperatures. India is likely to see a large drop in wheat production due to heat stress — about 8 percent if average global temperatures rise by 1 degree Celsius, according to one recent study.
  • Peaches, like many fruit trees, must experience enough chill during wintertime otherwise they get confused and don’t bloom properly. No bloom, no harvest. California’s Central Valley peach trees require about 700 “chilling hours” during the winter and scientists are predicting that by the end of the century, only 10 percent of the valley will reliably see that much chilling.
  • Coffee can’t take freezing temperatures, but it doesn’t like extreme heat, either. Brazil is the biggest coffee producer in the world, by far, but as the globe warms up, most of its main coffee-growing regions probably won’t be suitable for growing this crop anymore, due to heat as well as more frequent rainstorms.
  • Almonds are a dramatic illustration of how subtle shifts in climate can have huge effects. California’s farms rely heavily on snow that piles up in the Sierra Nevada mountains during the winter, and then slowly melts during the summer, delivering a vital flow of water to the state’s irrigation canals. As the climate warms, though, winter precipitation will arrive more often as rain, and the snow that does fall will melt much more quickly, leaving farmers scrambling for water to keep crops alive in late summer. Catastrophic shortages of water are especially bad for tree crops, of which almonds are the biggest. More at NPR

Q: How does deforestation affect climate change?

A: Deforestation is the destruction of forests in order to make the land available for other uses. Some common reasons for it are: to create room for cattle ranching, to harvest soy for feeding cattle, and to create ingredients for consumer items (such as the oil from palm trees). Currently, about 300 billion tons of carbon, 40 times the annual greenhouse gas emissions from fossil fuels, is stored in trees, according to Greenpeace. Deforestation releases that stored carbon dioxide into the air. According to the 2010 Global Forest Resources Assessment, trees are releasing nearly a billion tons of carbon into the atmosphere per year as we cut down an estimated 18 million acres of forest, roughly the size of the country of Panama, each year. According to National Geographic, the world’s rain forests could completely vanish in a hundred years at the current rate of deforestation. More at Live Science

Q: Why does it matter that the Trump administration is planning to make it easier for oil and gas companies to pollute the atmosphere with methane gas?

A: In an interview by Amy Goodman, Michael Mann says that methane is an even more potent greenhouse gas than carbon dioxide. Now, it exists in much lower concentrations, and it does not hang around for as long, but if we release enough methane into the atmosphere over the next decade or so, that could boost the warming that we see. At a time when the impacts of climate change are so obvious that not even the most fervent climate change denier can deny that they are there, we see efforts by the Trump administration to roll back the very policies—regulation of carbon emissions, in this case methane—that have the potential to stave off dangerous warming, that have the potential to help us meet our obligation to the Paris agreement so that we avoid catastrophic warming of the planet. More at Democracy Now

Q: Is climate change responsible for the California wildfires?

A: California has battled four of its five largest fires since 2012, and scientists have concluded that climate change has increased the frequency of extreme weather and will continue to do so. Even after major periods of rain, uninterrupted high heat can produce arid conditions quickly, which leads to big fires. A 2016 study published in the Proceedings of the National Academy of Sciences concluded that human-caused climate change is responsible for about half the additional drying that researchers have found since the 1970s, resulting in a doubling of the area forest fires have consumed since 1984. Climate change may also increase lightning strikes, which are a major source of wildfires, and generate the high winds that can drive big blazes. More at the Washington Post

Q: What effect do megafires have on carbon dioxide levels?

A: A megafire (defined by burning 25,000 sq acres–a bit smaller than Long Island) burned in Canada in 2014. In that case, it burned 7 million acres, scorching a region of boreal forest the size of Maryland. One result was that it released half as much carbon back into the atmosphere that all the plants, shrubs and trees in Canada typically store in an entire year. More at NASA

Does fracking for gas cause earthquakes?

A: While quakes can be caused by hydraulic fracturing — the high-pressure injection of fluid and sand into rock, opening cracks that release oil and gas — more often, it’s the underground injection of wastewater after fracking that is the culprit. The federal government posted this 2014 report here. More at National Geographic 

Q: How will the changing climate affect us in the next few decades?

A: After more than 10,000 years of relative stability—the full span of human civilization—the Earth’s climate is changing. As average temperatures rise, climate science finds that acute hazards such as heat waves and floods grow in frequency and severity, and chronic hazards, such as drought and rising sea levels, intensify. Read this report from McKinsey to explore the nature and extent of physical risk from a changing climate over the next one to three decades, exploring physical risk as it is the basis of both transition and liability risks. More at McKinsey