This graphic, by Boggis Makes Videos and put on YouTube just a few days ago, breaks all the rules of how to make effective, understandable graphs for the general public. However, if you follow all those rules, it is difficult or impossible to get certain message across. Therefore, this graphic is necessary if a bit difficult. I would like you to watch the graphic several times with a prompt before each watching so that you fully appreciate it. This will only take you six or seven minutes, I’m sure you weren’t doing anything else important.
Pass 1: How to read the graph
This graph’s basic data are temperature anomaly, not temperature, but difference in observed temperature averaged out over a month, using a baseline of 1961-1990. Global warming was already underway for this period, but it still works as a baseline. Anyway notice the scale shown at the beginning of the presentation.
The Graph shows the temperature anomaly across latitude, using a circle meant to represent the earth, so the north pole is on top, the south pole on the bottom, the equator half way between, etc.
The height of the graph’s bars, as well as their color, show the anomaly, but the beginning of the graphic shows you how far out, in standard deviations, the values are.
The Graphic display starts at 1900. The values are shown for each month, but they are 12 month moving average values, otherwise this graphic would give you a seizure.
So watch the first 20 seconds or so as many times as you need to, to fully understand these details.
Pass 2: It is getting warmer and weirder
On the first pass, just note that as the earth gets warmer, at sea and on land (see the two graphics at the bottom). Notice that the variation from year to year as well as the increase in temperature really takes off in the 1980s. Notice that the surface warmth values increase dramtically starting in the 1990s. Notice that things get really wild over just the last ten years or less.
Pass 3: Ends and middles
On your third pass, and this may take a few passes, notice the difference between the equatorial, temperate, and polar regions, as well as the difference between the two poles.
Consider that the increased warming in arctic regions compared to other regions affects many aspects of our weather.
Consider that the increases in temperate and tropical regions means that over some periods of time an increasingly lager area of the earth becomes uninhabitable without air conditioning.
Notice that the northern and southern hemisphere don’t have the same exact pattern.
Scott Adams is the creator of Dilbert, the once funny but now highly repetitive cartoon about a nerd who has a job in an office.
Dr. Gavin Schmidt is high up in the top ten list of world class climate scientists. He is Director of the currently under siege GISS Unit of NASA, where much of the climate science done by that agency is carried out. If you read my blog, you’ve read his work, because you also read RealClimate, where GS writes about climate science in a manner designed to be understandable to the intelligent, honestly interested, thoughtful individual.
Adams has a history of going after core science concepts, often substituting scientific reality with his own. He has done so with climate science.
And, he’s done it again. In a recent blog post (of yesterday) Adams tries to “convince skeptics that climate change is a problem”
This is a re-hash of earlier posts he’s written, in which he does the old denial two step. Of course climate change is real, he says. I’m not a scientist, he says. I don’t know jack about climate science in particular, he says. Then, he uses up piles of ink telling climate scientists how they’ve got all the science wrong.
His objective, I assume, is to spread and nurture doubt about climate science and science in general.
Dr Schmidt caught a tweet of Adams’, pointing to his absurd blog post, and responded with a series of tweets addressing all the things.
I wanted to preserve this excellent, well documented and richly illustrated TweetTextBook, and it occurred to me that you might want to see it too. So, here are the tweets.
Feel free to add additional relevant tweets to the comments, if you like. I hope this doesn’t break the Internet.
But since I'm in the mood for a totally futile exercise, here's why his points are disingenuous at best. Let's start with models… 1/n
The World Meteorological Organization has announced that they expect 2015 to be the warmest year on record, and that we are in the warmest five year period on record. We are speaking here of global surface temperatures, though similar descriptions probably apply to the upper 2000 meters or so of the ocean as well.
The global average surface temperature in 2015 is likely to be the warmest on record and to reach the symbolic and significant milestone of 1° Celsius above the pre-industrial era. This is due to a combination of a strong El Niño and human-induced global warming, according to the World Meteorological Organization (WMO).
The years 2011-2015 have been the warmest five-year period on record, with many extreme weather events – especially heatwaves – influenced by climate change, according to a WMO five-year analysis.
“The state of the global climate in 2015 will make history as for a number of reasons,” said WMO Secretary-General Michel Jarraud. “Levels of greenhouse gases in the atmosphere reached new highs and in the Northern hemisphere spring 2015 the three-month global average concentration of CO2 crossed the 400 parts per million barrier for the first time. 2015 is likely to be the hottest year on record, with ocean surface temperatures at the highest level since measurements began. It is probable that the 1°C Celsius threshold will be crossed,” said Mr Jarraud. “This is all bad news for the planet.”
Greenhouse gas emissions, which are causing climate change, can be controlled. We have the knowledge and the tools to act. We have a choice. Future generations will not.”
They have some nice graphics:
Caption for the graphic at the top of the post:
Global annual average near-surface temperature anomalies from HadCRUT126.96.36.199 (Black line and grey area indicating the 95% uncertainty range), GISTEMP (blue) and NOAAGlobalTemp (orange). The average for 2015 is a provisional figure based on the months January to October 2015. Source: Met Office Hadley Centre.
NOAA has just published September’s global surface temperature, which turns out to be 0.90C above their baseline (20th century average). According to NOAA, this is the highest value for September on record, 0.19C higher than last year, which was also a record. The graph above shows the year to date average, though September, for NOAA’s entire data set.
Ed Hawkins, a climate scientist at the University of Reading, recently tweeted a graph he produced to show global surface temperatures since 1850, noting that 2015 year to date broke his graph.
Using NASA GISS data, climate scientist John Abraham broke his graph too:
Using the NOAA data, I made the following chart, showing annual surface temperature measurements for their entire record through 2014. Then, I added an estimate for 2015, based on year to date numbers.
Every year the sea ice that covers the northern part of the Earth expands and contracts though the winter and the summer. The minimum extent of the sea ice is usually reached some time in September, after which it starts to reform.
Human caused greenhouse gas pollution has increased the surface temperatures of the earth, as measured on the land at about heat height with thermometers, and on the sea at the surface, mainly with satellites. Warming of the surface has continued apace for several decades, though with some expected squiggling up and down in how fast that is happening.
Greenhouse gas, mainly CO2, causes warming because of its heat trapping properties, and this warming (and the CO2 itself) set in motion a number of feedback systems that either push against warming or increase warming. Most of these feedback systems, unfortunately, are what we call “positive” feedbacks, though they are not “positive” in a good way. They are effects that increase the amount of warming beyond what would happen from just the CO2. One of the biggest global effects is an increase in the amount of water vapor carried by the atmosphere. Since water vapor is also a greenhouse gas, more CO2 -> more greenhouse effect -> more water vapor -> more greenhouse effect.
One of the bad effects of greenhouse warming is the melting of more ice in the Arctic during the summer. On average, less and less ice is left by the end of the melt season in September. Again, this amount squiggles up and down a bit, but it is a persistent downward trend. Since ice reflects sunlight away from the earth, a decrease in ice cover in the Arctic means more warming. This has both regional effects (such as an increase in melting of land-based Greenland glaciers) and a global effect. The regional effect is very important, because this has resulted in a phenomenon known as Arctic Amplification. This refers to the fact that of all the different regions of the earth, the Arctic is warming more than most other regions. The large scale systems of air movement that make up much of our climate, and thus control much of our weather, are shaped and driven in large part by the redistribution of heat form tropical areas (where the sun has a stronger warming effect) outward towards the poles. This redistribution shapes trade wind patterns and determines the location and strength of the jet streams. The relatively warmer Arctic has changed the basic shape and pattern of these major climatic features in ways that have caused significant changes in weather. The drought in California is caused in part by the persistence of a large jet stream meander caused, almost certainly, by Arctic Amplification and other changes in heat distribution in the northern latitudes. Another change is the increase in large scale precipitation events. Here in the twin cities, for example, the frequency of 3″ plus rainstorm over the year has changed from about one every two years to one every year, on average. Rainfall events of between 1 and 2 inches, and between 2 and 3 inches, have also increased.
There are two major properties of Arctic ice that should be considered. One, just discussed, is extent. Extent matters because of its direct effect on albedo, the reflection of sunlight back into space. Less ice extent, caused by warming, means even more warming. The other property is ice volume. Ice volume builds up over time. Thick ice includes ice from previous years that didn’t melt. The system is complex and dynamic, but a healthy Arctic ice ecosystem has a good amount of thick high-volume ice that persists through the melt season and forms the anchor against which annually re-freezing surface ice forms. The less ice volume, the less stable the Arctic Sea ice is, and the more difficult it becomes to reform. Exactly how this effect works depends on exactly which part of the Arctic one is in.
Over the last several decades, the volume of Arctic Sea ice has reduced by something like 80%. This is not good.
Andy Lee Robinson has made an amazing and highly instructive graphic showing the decline in Arctic Sea ice volume over the years. Here is the most updated version showing data up through this year, based on these data:
This is an animated visualization of the startling decline of Arctic Sea Ice, showing the minimum volume reached every September since 1979, set on a map of New York with a 10km grid to give an idea of scale. It is clear that the trend of Arctic sea ice decline indicates that it’ll be ice-free for an increasingly large part of the year, with consequences for the climate.
The rate of ice loss in the Arctic is staggering. Since 1979, the volume of Summer Arctic sea ice has declined by more than 80% and accelerating faster than scientists believed it would, or even could melt.
Based on the rate of change of volume over the last 30 years, I expect the first ice-free summer day in the Arctic Ocean (defined as having less than 1 million km² of sea ice) to happen between 2016 and 2022, and thereafter occur more regularly with the trend of ice-free duration extending into August and October.
By the way, those interested in computer technology will note that Andy’s graphic is produced on the most powerful and stable operating system, Linux, using OpenSource tools.
I produced the animation using hand-written perl and php code to create povray scripts, and scheduling task distribution using MySQL between 7 linux servers working in parallel to render 810 frames at 1920 x 1080 resolution. The “farm” renders 22 frames simultaneously taking between 1-2 hours per frame. On completion, ffmpeg combines the individual frames and music into a high quality mp4 video.
So, that’s cool.
Anyway, Andy has also created the now famous Sea Ice Death Spiral graphic, showing Arctic Sea ice volume since 1979, in a particularly helpful graphic style. Notice that the sea ice volume is fairly stable for several years, then starts to decline rapidly and continues to do so thereafter.
Sea ice extent has followed a similar pattern. Let’s have a look at this year in relation to the last several decades. First, this graphic made using the interactive graphing tool at the National Snow and Ice Data Center shows this year’s ice in relation to the average and standard deviation since 1979. Here we see that the ice extent has been following the lowest end of the two standard deviation spread. The lowest extent shown here is the fourth lowest since records began:
To add even more perspective, the next to graphics show the first ten years in the NSIDC data set, followed by the last ten years. In both cases, the thick black line is the average for the entire data set. This comparison clearly indicates that things have changed in the Arctic:
One of the things that people who wish to deny climate science usually start whinging about at this point in the discussion is that the Antarctic has had an increase in sea ice, and that somehow this all evens out. Let me briefly explain why this is incorrect.
There has been an increase in the extent of sea ice in the Antarctic, but there are at least two (maybe three) reasons for this. First, there has been a major increase in winds in the southern hemisphere caused by climate change. This includes winds coming off the Antarctic continent. These winds break up the sea ice and blow it around, opening areas between blocks of floating ice, which then freeze quickly. This causes an increase in extent of the ice. The other is the increase in fresh water entering the sea around Antarctic because the glaciers are melting. This fresh water allows the sea to freeze at a higher temperature, causing more ice. There may be other reasons having to do with currents of both air and water, and rainfall, also caused by climate change. So, climate change causes these changes in sea ice at both poles.
The increase in maximum sea ice in the Antarctic does not increase albedo because it happens in the dark. So the decreased global albedo in the Arctic is not offset by changes in the Antarctic. All of the regional ecological changes affecting sea life and so on can not be offset between the Arctic and Antarctic, because they are on opposite ends of the planet. Also, note, that this year we did not see an increase in Antarctic sea ice. Overall it is expected that global warming will turn around the Antarctic sea ice amount, and also, we are expecting Antarctic glaciers to begin melting at a higher rate over the next decade or so. It will be interesting to see what eventually happens. In any event, keep in mind that the Arctic and Antarctic are very different geographical regions. The Arctic is a sea surrounded by continents. The Antarctic is a continent surrounded by sea. We could not possibly expect the same things to happen in these two areas. The comparison often made by climate science contrarians is absurd.
That is a good question, and difficult to answer. If it turns out to be, it will be the warmest calendar year in the instrumental record, which goes back into the 19th century.
Regardless of what El Nino (ENSO) does, 2015 will be a warm year. Why? Because everything is warm and getting warmer and even if 2015 is less warm than 2014, it will be warm. There is no other possibility.
Even without the effects of El Nino, though, it is possible that 2015 will be warmer than 2014 because we see a lot of heat out there. If the present, relatively weak El Nino continues for a while, it will likely increase the chance that 2015 will be warmer than 2014. But current predictions suggest that 2014 will not only continue to have a strengthening El Nino, but El Nino conditions may either continue or repeat over 2015 and beyond. If that happens, not only is 2015 likely to be the warmest year in the instrumental record (since 1880) but 2016 may be in the running to be even warmer.
So far each month of 2015 has been very warm (see graph above) overall (the “zero” on the Y-axis of that graph represents the 20th century mean surface temperature). This month, April, is not excessively warm. Likely when April is plotted for 2015 on this graph, it will be either cooler then or around the same as last April.
Obviously we won’t know until the year is over, and given that climate change is a medium term phenomenon best measured in decades, we shouldn’t be in such a hurry to know these numbers. But, given that climate change is the existential issue of our day and the data become available month by month, we are not going to ignore the march of surface temperatures. We are going to, rather justifiably, be interested in what happens, month by month, as it happens.
At the end of the month, climate scientists such as my friend John Abraham, who is tracking global temperatures daily, will be able to produce a very good estimate of what the major data bases (such as NASA GISS, used here) will say, but those data bases won’t be officially updated until around the middle of the following month or so. So stay tuned.
Added: For those keeping track, I made a new version of the above graph. The red line represent the monthly anomaly values required (on average) for the rest of the year for 2015 to equal 2014. I also extended the Y-axis to 100 because the warmest month in the GISS database is in the 90s, just in case such a very warm month occurs. It is likely that April 2015 will not e as warm as April 2014 but it will likely be above the red line.
The New York Times put the news of 2014 being the warmest year on their front page, in the precious space known as “Above The Fold.” But, the venerable paper of record continues to give credence to science denialists by calling them “skeptics,” and continues to imply that there really is a debate between consensus based science and politically motivated denial of science. To underscore this point I created the above graphic.
This is serious. A highly regarded and widely recognized planetery physicist put together the most dangerous scientific ingredients that exist: skepticism of the established science, a comprehensive list of hypotheses that stood in opposition to that established science, a huge amount of data, a healthy amount of funding including a good chunk from energy companies that mainly sell fossil carbon based fuels, and a hand selected research team of others who were also skeptics.
In the end, he came up with an explanation for what people call Global Warming. Personally, I believe him. I think he has it right. Whatever you were thinking as the cause of global warming, you have to look at this work and if you have not come to the same conclusion, you should reconsider.
Here’s an interview which includes an explanation of the whole process.