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The effects of global warming are frequently projected decades into the future, but two recent reports -- one from theU.S. Global Change Research Program
and the otherfrom the U.N.
-- put into sharp focus visible consequences of our warming planet. An increase in temperature, extreme weather, loss of ice and rising sea level are just a few of changes we can measure right now. Let's take a look at some of the most concerning trends.BLOG: War Of The Words: Climate Change Or Global Warming?
Glaciers are shrinking worldwide and permafrost is thawing in high-latitude and high-elevation areas, reports this year's Fifth Assessment Report from the Intergovernmental Panel on Climate Change.BLOG: Dire Outlook For Climate Impacts, New Report Says
Only a few extinctions are attributed to climate change, reports the IPCC, but climate change that occurred much more slowly, over millions of years, caused major ecosystem shifts and species extinctions. Land and sea animals are changing their geographic ranges and migratory patterns due to climate change.NEWS: Climate Change: Why Haven't We Done More?
Sea level around the world has increased by about 8 inches since 1880, reports the 2014 National Climate Assessment, which projects a 1 to 4 foot rise by the end of the century.PHOTOS: Craziest Environmental Ideas (That Could Work)
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Excess CO2 is dissolving in the ocean and decreasing the pH of seawater. The ocean is about 30 percent more acidic than it was in pre-industrial times. More acidity in the oceans makes it harder for animals to form calcium carbonate shells and skeletons and erodes coral reefs.11 Health Threats from Climate Change
The probability of a Sandy-like storm deluging New York, New Jersey and other parts of the East Coast has nearly doubled compared to 1950, according to the American Meteorological Society. Even weaker storms will be more damaging now than they were 10 years ago because of rising sea levels. Superstorm Sandy cost the nation $65 billion, according to the 2014 National Climate Assessment, and 2012's Hurricane Isaac cost $2.3 billion.
The global sea level rises along with the temperature for two major reasons. For one, heat causes water to expand, which causes the existing water to take up more space and encroach on the coast. At the same time, ice at the poles and in glaciers melts and increases the amount of water in the oceans.PHOTOS: Melting Glaciers
Across the United States, heavy downpours are on the rise, especially in the Northeast and Midwest. Increases in extreme precipitation are expected for all U.S. regions, reports the 2014 National Climate Assessment.NEWS: Shrinking Greenland Glacier Smashes Speed Record
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The most recent IPCC report states with "very high confidence" that current climate-related extremes like heat waves, droughts, floods, cyclones and wildfires are showing that countries around the world, at all development levels, are significantly unprepared. The American Meteorological Society estimates that approximately 35 percent of the extreme heat in the eastern United States between March and May 2012 resulted from human activities' effects on climate. The AMS warned that deadly heat waves will become four times more likely in the north-central and northeastern United States as the planet continues to warm.NASA: Global Warming Goes On
Americans are sweltering this week and mid-summer temperature maps are covered in big belts of red and dark red.
In fact, the U.S. Energy Information Administration forecasts that the typical U.S. home will use an average of 1,044 kilowatt-hours per month this summer, 3.7 percent higher than the same period last year because there are more "summer cooling degree days."
But the solution to staying cool by cranking up the air-conditioning has a dark side: the energy it uses also happens to be a big contributor to climate change.
Air-conditioner technology has come a long way since Willis Carrier invented the modern air-conditioner in 1902 using ice and fans. In 1980, an individual room air-conditioning unit used 1,474 kWh per year and cost $178 to run, according to figures by the U.S. Environmental Protection Agency. Today, an EPA "Energy Star"-certified room a/c uses only 597 kWh/year and costs $75 to run.
But while units use less energy, we're using more of them.
In fact, the amount of electricity burned per air-conditioned household increased 38 percent since 1990, according to Stan Cox, an analyst at The Land Institute in Salina, Kansas, and author of the book "Losing Our Cool: Uncomfortable Truths About Our Air-Conditioned World."
Today, nearly nine of 10 Americans use a/c to cool their homes. Cox is one of the remaining 10-percenters who doesn't use one.
"If we are going to have to decide that there are some technologies that are not necessities, maybe we can do without some of them," Cox said. "Until a half-century ago a/c was not a necessity, maybe we should think about that again."
Cox is a big proponent of passive forms of cooling, like taller ceilings in houses, cross-ventilation, porches to shade windows, over-door transoms, ceiling fans and roof exhaust fans to move hot air out of the house. Proper insulation in homes also allows the cool air to remain inside rather than escaping outside.
Still, last week, as the temperature outside reached 107 degrees in his Kansas home, Cox tried every method he could think of to stay cool.
"One by one they all failed except going to the basement," he said.
Cox agrees that air conditioning has improved people's lives. Studies show that it helps sleep patterns, makes workers more efficient and prevents heat stroke deaths in the summer.
The U.S. EIA predicts that Americans' energy use to keep cool will grow 1.5 percent a year through 2040. Worldwide, that figure is a lot bigger.
UC Berkeley business professor Lucas Davis has been looking at air-conditioning use in developing nations. China and India are increasing their use of air conditioning rapidly and that's feeding their growing demand for more energy, most of which comes from the burning of fossil fuels.
As global temperatures rise over the next few decades, the demand for cooler buildings will only get worse, according to study published in May by Davis in Proceedings of the National Academy of Sciences that looked at the rise in air conditioning in Mexico.
"We describe both how electricity consumption increases with temperature given current levels of air conditioning, and how climate and income drive air-conditioning adoption decisions," the study concluded.
"We then combine these estimates with predicted end-of-century temperature changes to forecast future energy consumption. Overall, our results point to air-conditioning impacts being considerably larger than previously believed.”
Davis says it's a good thing that developing nations are getting wealthier and want to improve their quality of life, which includes staying cool. "The challenge is managing that demand for electricity," he said.
It also means that means that the desire for a more comfortable and cooler home and office will likely make the planet bake even faster.
For his part, Davis is another 10-percenter who doesn't have air conditioning in his Oakland, Calif., home. He's lucky enough to live near the San Francisco Bay, which moderates summer heat. Davis cuts his home energy use from appliances and other power sources voluntarily during peak demand days.
On Tuesday, he plans to give up his washing machine and dishwasher, for example, after receiving a notice from his utility company.
Davis believes common-sense building design, as well as so-called "dynamic pricing," in which the cost of electricity goes up as the demand rises, is the best way for Americans to reduce energy needed for air conditioning.
"Rather than having a blackout," Davis said, "prices would go up and people would consume less."