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The 5 Most Sobering Charts from the IPCC Climate Report

The first installment in the U.N. Intergovernmental Panel on Climate Change’s latest scientific assessment on climate science came out on Friday, and it’s loaded with dense terminology, expressions of uncertainty, and nearly impenetrable graphics.

But we'll make it simple for you. Here’s what you need to know, in number and chart form.

Global average surface temperature change to date in degrees Celsius.
Credit: IPCC Working Group I.

1.6°F: Amount that globally averaged combined land and ocean surface temperatures increased between 1901-2012.

0.54°F to 8.64°F: How high global average surface temperatures are likely to climb by 2081-2100 relative to 1986-2005 levels, depending on future amounts of greenhouse gases in the air. The report found that the global mean surface temperature change by 2100 is likely to exceed 2.7°F relative to the period betwen 1850-1900 in all but one of the emissions scenarios.

Map of multi-model mean results for different greenhouse gas concentration scenarios of annual mean surface temperature change in 2081– 2100.
Credit: IPCC Working Group I.

The report also found that the past 30 years have been the warmest three decades since instrument records began during the 19th century, and that in the Northern Hemisphere, the past 30 years have likely been the warmest in more than 1,000 years.

Decadal average surface temperatures.
Credit: IPCC Working Group I.

10.2 to 32 inches: How much mean global sea level is projected to increase by 2081-2100. The scenario with the highest amounts of greenhouse gases in the atmosphere shows a mean sea level rise range between 21 and 38.2 inches, which would be devastating for numerous highly populated coastal cities at or near current sea levels, from New York to Hong Kong.

Projections of global mean sea level rise over the 21st century relative to 1986–2005 from the combination of the computer models with process-based models, for greenhouse gas concentration scenarios. The assessed likely range is shown as a shaded band. The assessed likely ranges for the mean over the period 2081–2100 for all scenarios are given as coloured vertical bars, with the corresponding median value given as a horizontal line.
Credit: IPCC Working Group I.

By comparison, the previous IPCC report in 2007 projected a global sea level rise of .7.1 to 23.2 inches by 2100, but it did not include the influence of rapid melting of the Greenland ice sheet as well as portions of Antarctica because not enough information was known at the time.

0.07 inches per year to 0.13 inches per year: Rate of global average sea level rise during the 1901 to 2010 period compared to the 1993-2010 period.

The report found that the rate of sea level rise is accelerating as the oceans expand as they warm, and global ice sheets melt.

34 gigatons per year to 215 gigatones per year: Average rate of ice loss from Greenland during 1992-2001 and 2002-2011.

3.5 to 4.1 percent per decade: Annual mean Arctic sea ice extent rate of decline during 1979-2012. The report found that there is “medium confidence” that Arctic summer sea ice retreat and sea surface temperatures during the past 30 years were unusually high in the context of at least the past 1,450 years.

90 percent: Amount of the extra energy in the Earth’s climate system that is going into the oceans, where it is being stored, eventually to manifest itself in warming air temperatures.

11.7 percent per decade: The rate of decline in June snow cover in the Northern Hemisphere during the 1967-2012 period.

Global mean surface temperature increase as a function of cumulative total global CO2 emissions from various lines of evidence. Multi-model results from a hierarchy of climate-carbon cycle models for each RCP until 2100 are shown with coloured lines and decadal means (dots). Some decadal means are indicated for clarity (e.g., 2050 indicating the decade 2041−2050). Model results over the historical period (1860–2010) are indicated in black. The colored plume illustrates the multi-model spread over the four RCP scenarios and fades with the decreasing number of available models in RCP8.5. The multi-model mean and range simulated by CMIP5 models, forced by a CO2 increase of 1% per year (1% per year CO2 simulations), is given by the thin black line and grey area. For a specific amount of cumulative CO2 emissions, the 1% per year CO2 simulations exhibit lower warming than those driven by RCPs, which include additional non-CO2 drivers. All values are given relative to the 1861−1880 base period. Decadal averages are connected by straight lines.
Credit: IPCC Working Group I.

365 Gigatonnes: Amount of carbon dioxide (CO2) emissions from fossil fuel burning and cement production since 1750. Emissions from other sources, such as deforestation, yields cumulative manmade emissions of 545 gigatonnes of carbon since 1750.

Because CO2 has such a long atmospheric lifetime, with some molecules lingering in the atmosphere for hundreds of years, scientists have to take into account the cumulative total of CO2 emissions in order to project future warming.

This graphic shows cumulative CO2 emissions and the likely temperature changes associated with them based on the IPCC’s four greenhouse gas concentration scenarios. The bottom line is that holding global warming to at or below 3.6°F is going to be incredibly difficult. The report found that to have at least a 66 percent chance of holding warming to below that threshold will require cumulative CO2 missions from all manmade sources to stay below 1 trillion metric tons of carbon since 1861.

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« Climate in Context


By Nancy Wells (Vancouver BC Canada)
on September 27th, 2013

When will we hear of “real” strategies to combat this trend.

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By Troy Verbrugge (WESTMINSTER, CO 80031)
on September 27th, 2013

Was it brought up on the “Decadal average surface temperatures.” graph that there seems to be a 30-40 year pattern of drops and rises?  One thing to note from that 30-40 year pattern is that the rises are getting bigger and the drops are getting smaller.

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By Allan McKillen (Sleaford)
on September 28th, 2013

I am a science student studying with the Open University. I have a special interest in climate and everything that affects it.
I have been looking at the report above and comparing the “key” indicators to the reports printed in today’s press. Mainly the Telegraph and the Guardian and even as a science student I find it very difficult to get a sense of consistency with the data. Would it not be helpful to set a “standard” model of reporting the time on one axis from a standard point of reference and not have a constant array of everything from 1880-1950 as a starting point? It is also to possible extrapolate to the n(th) degree however I don’t see much merit in doing this as there are a myriad of variables that need to taken into consideration.

Regards A. McKillen

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By gary wilson (North East, MD 21901)
on September 28th, 2013

I’m a retired science teacher.  This has been predicted since the 70” and before.  We have done nothing about it.  We are toast.  Our children will damn us for what we have done.

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By trevor collins (new zealand)
on September 28th, 2013

greetings to one and all…when will this man get back to railway engine driving, in stead of trying to forecast the weather/climate change/or is global warming???

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By Vera Mark (Germany)
on September 29th, 2013

Thanks for this. However, I think it would be helpful to add the °C equivalents in temperature rise, as much of the world uses degrees Centigrade, and also to give a very brief explanation of the RCP scenatios.

The real debate, though, should be about what kind of future we want. Science with all its details is being used as a proxy, haggling over degrees of uncertainty. Let’s talk values instead.

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By Len R. Holliday (Belton, S.C. 29627)
on September 30th, 2013

I’m Len Holliday, Lead Forecaster at Firsthand Weather. So you will know a little bit about me, I have a A.A. Degree in Meteorology and a B.S. Degree in Mathematics. Graduate work at several different Universities in the field of economics, finance and Meteorology. So, I do have a science back-ground! I’m a retired stockbroker of 20 years. I was a grain trader as well as weather expert for several Wall Street firms during that 20 years. I’m sorry to tell you this but the whole Global Warming idea from the top to bottom is a great American Hoax driven by greed, money and power! Everyone in the world that is out pushing man-made Global Warming has an agenda! It’s called money! Look at Al Gore. Ten years ago his net worth was $2 million and today he is worth $300 million. Not bad for a Country Boy from Tn. with no science background at all! What does that tell you. We have known for years that CO2 only goes up after temperatures have gone up. Co2 is not a leader but a follower!  We know for sure that the world is getting colder and not warmer. The Warming is now in the history books. It all stopped and turned over to a colder cycle in the mid-90’s and we have ever reason to believe we are now in the early stage of the next Little Ice Age and the U.S. is not ready for what is coming. Great earthquakes and even volcanoes. The warm cycle will be hit hard by Nature. If Nature gets out of yuack no matter the cause, it will find a way to make itself right again. Nature is a lot smarter than man could ever dream about being. The sun is going into a cycle for the next 30 years of no sunspots. Bad things are on the way and soon. Read the book called Cold Sun. This guy has found the truth! Thanks! Len Holliday(

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By Josh Calcino (Brisbane)
on September 30th, 2013

Like Allan, I have am an undergraduate studying science, namely physics and math to eventually get a position in the Bureau of Meteorology. I hope that this latest IPCC report opens the eyes of many “skeptics” out there. Politicians, like Christopher Monckton, need to stay the heck out of the science. Leave the science for the scientists, politicians can then decide what appropriate action needs to be taken to address the issue. Monckton has openly lied to a vast number of people who then call themselves “skeptics”.

Unfortunately we have one of these politicians as our prime minister..

The real sad thing is that it is very difficult to get the carbon out of the atmosphere, trees can’t do it by themselves now. With current technology, to my knowledge, it still costs over $100 per ton to remove CO2 from the air..

It truly concerns me where we are heading as a species, the universe is full of mystery and awe. Our civilisation might not make it past the next few centuries, we are at a very critical time in our history. I urge anyone reading, to do all they can to ensure the survival of our species and all species on this fragile little world. You don’t need to be a scientist.

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By S Katz (Boston)
on September 30th, 2013

What is the effective half life of methane in the upper atmosphere?

The mechanism that breaks down CH4 is a fixed process: the more methane increases, the longer the effective half-life is, compounded by an unknown upper limit as to how much CH4 can be broken down. If the process that breaks down CH4 is not linear [solar energy is fixed in this equation, for instance] and has reached a compression point, then the effective half-life of CH4 in the upper atmosphere is increasing. To what extent it could be increasing is not known, as there’s not enough data to quantify this parameter.

Just this one parameter, the effective half-life of CH4 as a GHG could reveal that these charts that are grossly underestimating global warming potential.

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By Michelle M
on October 2nd, 2013

Len Holliday:
Spending half your time trying to establish your (non-existent) credentials to discredit real scientists makes you look foolish. You’re a mathematician and a stockbroker who works for big business interests, not humanity. Your 2-year degree in meteorology qualifies you to make short-range forecasts on TV based on data others collect. It does not qualify you to discredit scientists who know what they are talking about. Spouting nonsense about volcanoes and sunspots is ridiculous, and all the data shows that the climate is warming.  So take the money that Big Business gave you to discredit real science, and do something that will help prevent humanity and half the life on this planet from becoming extinct.

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on October 3rd, 2013

What have we left to our children.

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By Constantine Saltis (Sydney-Australia)
on January 31st, 2014

I am seriously hoping to read in one of these reports, at some stage,  what happened to the heat released into the earth’s atmosphere by war and related activities since the beginning of the twentieth century and up to the year 2005 and beyond. Is it permissible in a scientific presentation to omit such a significant component? 

C. Saltis








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By tom
on February 25th, 2014

Google “Muller—Conversion of a Ciimate-Change Skeptic” 

Check out Berkeley Earth Project

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