News Section
Stories from Climate Central's Science Journalists and Content Partners

5 Must-See Charts From Major New U.S. Climate Report

Repost This

A major new federal climate science assessment, released in draft form on Jan. 11, finds that “climate change is real and accelerating,” and that myriad impacts are already being felt in the U.S., from more frequent, hotter heat waves, to coastal flooding and precipitation extremes. The report, which is the first since 2009 to systematically examine the effects of global warming on the U.S., bolsters some of the conclusions of the previous report and cites new findings showing that the country is already experiencing a wide range of disruptive impacts from global warming, primarily through the changing frequency and severity of weather extremes.

For example, the report cites “strong evidence” that manmade global warming has “roughly doubled” the probability of extreme heat events, such as the record hot summer of 2011 in Oklahoma and Texas. It also notes that sea level rise is exacerbating storm surge problems along the East and Gulf Coasts, and that sea level rise played a role in exercerbating the impacts of Hurricane Sandy.

Global annual average temperature (as measured over both land and oceans; scale on left) has increased by more than 1.4°F (0.8°C) since 1880. Red bars show temperatures above the long-term average, and blue bars indicate temperatures below the long-term average. The black line shows atmospheric carbon dioxide (CO2 concentration in parts per million (ppm); scale on right. While there is a clear long-term global warming trend, some years do not show a temperature increase relative to the previous year, and some years show greater changes than others. These year-to-year fluctuations in temperature are due to natural processes, such as the effects of El Niños, La Niñas, and the eruption of 12 large  volcanoes. Figure source: NOAA NCDC. Temperature data from NOAA NCDC 2012; CO2 data from NOAA ESRL 2012.
Click to enlarge the image. Credit: National Climate Assessment.

Many news outlets have already provided broad summaries of the draft assessment, including the The GuardianWashington Post, Los Angeles Times, Nature, and the Huffington Post. (The executive summary from the report itself is posted below.) But digging deeper through the nearly 1,200-page report reveals there are myriad charts that update past findings on climate change, and which take advantage of recent advances in computer modeling to provide new insights as well.



First and foremost, the report strongly states that human activities — mainly the burning of fossil fuels for energy, which emits heat-trapping greenhouse gases — are changing the climate in ways that are already harming the U.S.

"Climate change is already affecting the American people," the report said, citing extreme weather events, rising and acidifying seas, in particular. "These changes are part of the pattern of global climate change, which is primarily driven by human activity." 

The colors on the map show temperature changes over the past 20 years in °F (1991-2011) compared to the 1901-1960 average. The bars on the graphs show the average temperature changes by decade for 1901-2011 (relative to the 1901-1960 average) for each region. The far right bar in each graph (2000s decade) includes 2011. The period from 2001 to 2011 was warmer than any previous decade in every region. (Figure source: NOAA NCDC / CICS-NC. Data 11 from NOAA NCDC. )
Click to enlarge the image. Credit: National Climate Assessment.

The report said that the U.S. has already warmed by 1.5°F on average since 1895, with more than 80 percent of that increase occurring since 1980, and it projects a further warming of up to 4°F during the next few decades. Depending on how successful the global community is at slashing emissions of greenhouse gases -- with little success so far -- the report projects the U.S. will warm between 3°F to as much as 10°F by the end of the century. According to the report, the world is currently on a path to exceed the highest emissions scenario put forward by the U.N. Intergovernmental Panel on Climate Change (IPCC), which is an indication that the highest-warming scenario may be the most plausible one at this time.

The largest uncertainty in projecting future climate change is the level of emissions. The most recent model projections (shown above) take into account a wider range of options with regard to human behavior; these include a lower emissions scenario (RCP 2.6, top left) than has been considered before. This scenario assumes rapid reductions in emissions – more than 70 percent cuts from current levels by 2050 – and the corresponding smaller amount of warming. On the high end, they include a scenario that assumes continued increases in emissions (RCP 8.5, bottom right) and the corresponding greater amount of warming. Also shown are temperature changes (°F) for the intermediate scenarios RCP 4.5 (top right, which is most similar to B1) and RCP 6.0 (bottom left, which 4 is most similar to A1B; see the Appendix). Projections show change in average surface air temperature in the later part of this century (2071-2099) relative to the late part of the last century (1971-2000). (Figure source: NOAA NCDC / CICS- 7 NC. Data from CMIP5.)
Click to enlarge the image. Credit: National Climate Assessment.

A key point regarding future warming is that much depends on choices made during the next one to two decades, and how sensitive the climate system is to the continued buildup of greenhouse gases. "There is mounting evidence that the costs to the nation [of global warming] are already high and will increase very substantially in the future, unless global emissions of heat-trapping gases are strongly reduced," the report said.

The colors on the map show annual total precipitation changes (percent) for 1991-2011 compared to the 1901-1960 average, and show wetter conditions in most areas (McRoberts and Nielsen-Gammon 2011). The bars on the graphs show average precipitation differences by decade for 1901-2011 (relative to the 1901-1960 average) for each region. The far right bar is for 2001-2011. (Figure source: NOAA NCDC / CICS-NC. Data from NOAA NCDC.)
Click to enlarge the image. Credit: National Climate Assessment.

The report details precipitation changes across the U.S., and shows that while many regions are getting wetter in response to the warming climate, other areas are drying. In particular, the report shows that the Southwest, Southeast, and the Rocky Mountain states have seen precipitation decreases. These trends are exacerbating water supply concerns and increasing drought and wildfire risks as well. 

The report is the product of more than 240 experts from multiple agencies and scientific institutions. It is now subject to public comment, and will undergo a review by the National Academy of Sciences, National Oceanic and Atmospheric Administration (NOAA), and other government agencies, before being transmitted to the White House and Congress. The report draws from studies published through July 31, 2012, although it also includes references to extreme events that happened after that date, such as Hurricane Sandy, which occurred in late October.

Related Content:
Hansen Study, Extreme Weather Tied to Climate Change
ew Reports Show Impact of Manmade Global Warming
OAA: 2012 Hottest and 2nd-Most Extreme Year on Record
urging Seas: Sea Level Rise Map Tool
ea Level Rise May Eclipse Three Feet By 2100
Ongoing Coverage of Historic Hurricane Sandy


By F. L. Hurst (Absecon, NJ 08201)
on January 14th, 2013

I recently visited Basto Village. It’s a colonial settlement on the Wharton Park.  They have an ice house where they harvest ice from the frozen lake to use for refrigeration in the summer.  I don’t think that would work to well anymore.

Reply to this comment

By Robert Oldham (45387)
on January 15th, 2013

Because the US, with 6% of world population, produces 20% of climate-affecting emissions and consumes 25% of the world’s energy resources, it would seem appropriate for this report to put greater emphasis on the impacts, on the rest of the people of the world, of US contributions to the problems of climate change. Americans, being generally wealthier than most countries, tend to assume that technology and adaptation will solve the problems, forgetting that most of the rest of the world’s population do not have access to possibly mitigative technologies nor to the resources necessary for adaptation. Thus the US has the potential to inflict major harm on other people of the world by an historical tendency to “go it alone” on issues like climate change that actually affect the entire globe and all of its people.

Reply to this comment

By Jonnie Hyde (Battle Ground, Wa)
on January 16th, 2013

No climate report should talk about benefits, such as longer growing seasons in some areas, as it perpetuates the idea that some people will come out of this as winners. We are on a course to human extinction, and if we don’t raise the level of alarm to a volume that breaks through denial, we are toast. Climate scientists need to stop trying to market and sell the story as to make it palatable. It is not palatable, it is a global catastrophe.

Reply to this comment

By Rodney Cappel (McCook Ne, 69001)
on September 15th, 2013

I think you are very vain to think you can change global weather. It is not the “smoke” from fossil fuels that is heating up our globe but the fact that we are putting less into the atmosphere,(a large volcano will cool the earth for at least two years) the raise in Colorado temp and else where is from concrete and asphalt,- you can walk barefoot in august on the prairie but you wont do that on a street, sidewalk or the top of all your houses, you need to calculate how much heat is being radiated off of everything manmade that is here now that wasn’t there even 30 years ago, it is not the smoke from the car but the heat from the engine and the heat that radiates from the surface , our skyscrapers have two sides facing the sun most of the time where there was once flat surface of grass. try to sleep on a dark tennis court or under a tree in august on a sunny day. How many more air conditioners are running now than were in 1970 in Colorado, maybe it is those huge houses you all own and only use two rooms in???... Now I grew up in the 70’s I know how dirty and polluted things were getting, I know we need to keep working toward making things better and cleaner, conservation is a very good thing just don’t be narrow minded about where the heat is coming from. Everything we put out and use IS a heater if the sun shines on it.

Reply to this comment

By jan (Los Angelez/CA/90041)
on September 17th, 2013

Looks pretty bad.  We need to reverse course or it will be the Titanic for our species. Dr. Hansen and many economists say a price on carbon would slow our descent.  There are even"green T Baggers” who want results,not more jive and delay.

Reply to this comment

Name (required):
Email (required):
Enter the word "climate" in the box below:

[+] View our comment guidelines.

Please note: Comment moderation is enabled. Your comment will not appear until reviewed by Climate Central staff. Thank you for your patience.