2014, hottest year on record

3 01 2015
Mark Cochrane

Mark Cochrane

Well, by NOAA’s measure at least, 2014 is officially the warmest year on record for the globe.This is primarily notable because it was not an El Nino year, when new highs are normally achieved. Still, the main reason we have achieved this dubious record is because of the rising temperatures of the world’s oceans, with 7, maybe 8, consecutive new highest monthly ocean temperatures. Some may quibble about the standing of 2014 in the global record depending on which temperature series they prefer (NOAA, NASA-GIS, HAD-CRU, etc) but all will show it as very high, regardless.


It is hard to be ‘shocked’ by this new record temperature because these ‘records’ seem to fall every couple of years and will continue to do so for the foreseeable future. What is under-appreciated is that these records are like trying to spin whether the US deficit is larger than the previous year or not. The key point is not whether it is a little bigger or smaller, it is the fact that we have a financial deficit that is the problem, our debts grow larger and larger year after year. In the case of the climate, what matters is the energy balance of the planet. We are gaining heat every single day of every single month of each and every year. December marks the 358th consecutive month that the planet was warmer than ‘average’. The end of February will mark 30 straight years where every month the Earth contains more energy than the previous year. If things were anywhere near stable, half of those months should have been below average to balance the years that were above average. Try to flip a coin and get heads or tails 360 times in a row. Good luck even getting 10 in a row (that’s a 1 in 1000 chance). Now try doing that 36 times in a row and you begin to get the mind bogglingly unlikeliness of this being a ‘natural’ variation. Anyone care to bet that we are going to experience 360 cooler than average monthly temperatures now?

During 2014, much of the continental United States was colder than normal but it was just about the only place on the planet experiencing cooler temperatures. It doesn’t matter what temperature one location experiences in any given year when we are talking about ‘global average temperatures’. It is the composite of all regions that make the difference. The cumulative warming is not only raising temperatures, it is also eroding the last vestiges of globally cooler times, as seen in the cumulative mass loss from the world’s alpine (mountain) glaciers. As glacial mass goes down, sea levels go up.

Straight from the Glacier National Park website:

It has been estimated that there were approximately 150 glaciers present in 1850, and most glaciers were still present in 1910 when the park was established. In 2010, we consider there to be only 25 glaciers larger than 25 acres remaining in GNP.

The changes in global temperatures and glacial mass are academic arguments that don’t show up in most people’s day to day lives but they are the underlying trends that tell all of us that the world is changing climates whether we choose to recognize this or not.

If we were suddenly to stop producing greenhouse gases (GHGs), the positive feedbacks for methane, for example, would barely change, ‘if’ we managed to hold the atmospheric aerosol level constant, but this is a really big caveat (more on this later)! The tundra melting is responding to excess heat already accrued, not the amount of new greenhouse gases each year. Even if we were able to somehow stop the growth of anthropogenic GHGs, this would be like stopping the deficit being run by the US (and every other country’s) government. While this would be better than having a deficit, you would still have to pay the annual interest on the total debt that you have already accrued. Our ‘interest’ payments are currently getting soaked up by the world’s oceans, and melting ice and permafrost areas. The debt we have already accrued (energy heat content) would still have us on a path for 3-4C and 40 m sea level rise over the next several hundred, to thousand years. However, if we really did stop all anthropogenic GHG emissions during that time, the planetary scrubbing system (slow feedbacks) would temper things a bit.

Back to that caveat on the aerosol levels though. If we somehow stopped all anthropogenic GHG emissions, the tundra melting would likely accelerate since we’d be facing a sudden pulse of heat equivalent to around 0.8C. Currently the aerosols (pollution) that we spew into the atmosphere create a haze that reflects about 50% of the excess solar heating that we should be receiving due to current GHG levels. While CO2 hangs around in the atmosphere for several hundred years, aerosols only stay floating around for weeks to months. Therefore, if we suddenly stop emitting GHGs then shortly thereafter we will experience a rapid doubling of the excess energy level reaching the surface of the planet. Although the sudden stopping of all greenhouse gas emissions is an unlikely event, anything that reduces the amount of atmospheric pollution (aerosols) will proportionally have the same effect. The biggest possibility I can see on the near horizon would be China implementing their version of the Clean Air Act. Good for local health of their populations but the world will warm more quickly. The same thing goes for any global shift to ‘green’ energy.

Cleaning up the atmosphere is not a bad thing to do but it will expose us more quickly to the climate debt that we have already accrued. Nature’s debt collectors will get their payments from us eventually.

As for 2015, if we get anything other than a very short and mild El Nino, then 2015 should rapidly supplant 2014 as the warmest year on record. Whenever the current phase of the Pacific Decadal Oscillation ends  (PDO) we will be due for another several years of rapid warming. Barring a mega-volcanic eruption near the equator or a massive meteor strike, we won’t be seeing any global temperatures below the ‘average’ any time soon.

Solar theories of recent global climate change, have at least one major problem – they do not match observations.

For the last 50+ years the average solar irradiance (bold blue line) has been stable or even dropping, especially in more recent years. However, as everyone knows, global temperatures have continued to rise during these decades. The sun cannot be the cause because unless the irradiance level is rising we are not going to be getting more heating.

When you try to model the Earth’s climate using only observed ‘natural’ forcings (e.g. the sun and volcanic eruptions), you do not get a very good match with global temperatures (Meehl 2004). That black line is global temperatures marching away from control by natural forcings.

If you only use anthropogenic forcings (man-made greenhouse gases, aerosols, ozone), you get a much better fit with temperature.

Finally, and not surprisingly, if you include natural and anthropogenic drivers you get a very good fit with observed temperature changes over the decades.

The sun is fundamental to life on Earth and is the engine that drives our climate but recent (and expected) changes in solar irradiance explain very little of recent global warming. We are amplifying the amount of heat that we get from the solar radiation that we receive by trapping it with more and more greenhouse gases.

We own this mess. Time we started doing something about it.

Happy New Year!




6 responses

3 01 2015

> “Well, by NOAA’s measure at least, 2014 is officially the warmest year on record for the globe” – apart from alternative measures such as – “NOAA, NASA-GIS, HAD-CRU, etc” – and to prove it, here is a piece of pap TV journalism from NBC.

Mark Cochrane is just a spin merchant. Given several measures, only one of which makes 2014 the hottest, that’s the one he chooses to highlight. No attempt is made to try explain why all these respectable organisations come up with different figures, or how they have compared over time. Just grab the scariest headline and run with it.

> The end of February will mark 30 straight years where every month the Earth contains more energy than the previous year.

Except that the figures for January and February 2015 haven’t happened yet, so that’s a prediction, not a fact. And why not choose the timeframe of the last 30 years (or 40 or 50) for which we have real records? – because that would spoil the story.

Then he sets up and knocks down the straw man argument of Solar Radiance and Volcanic Eruptions, which all climate scientists agree is not the whole story.

And finally the conclusion – “Time we started doing something about it.” Really? Let’s start with not spinning everything to be as SCARY as possible.

3 01 2015

EXCEPT he is not a spin doctor….. he’s a real climate scientist who writes submissions to IPCC.

5 01 2015

I sent Mark an email about your complaints, and pointed me to this:

There are 5 major sources of global temperature data which are most often referred to. Three of them are estimates of surface temperature, from NASA GISS (Goddard Institute for Space Studies), HadCRU (Hadley Centre/Climate Research Unit in the U.K.), and NCDC (National Climate Data Center). The other two are estimates of lower-troposphere temperature, from RSS (Remote Sensing Systems) and UAH (Univ. of Alabama at Huntsville). All are anomaly data, i.e., the difference between temperature at a given time and that during a baseline period. They tend not to be on the same baseline; for GISS the baseline is 1951 to 1980, for HadCRU it’s 1961 to 1990, for NCDC it’s the 20th century, and for satellite data the baseline is 1979 to 1999. Since they use different baselines, they’re on a different scale, i.e., each has its own zero point for temperature. To compare them, we need to use the same zero point for all.

They also don’t cover the same time span. HadCRU starts first, beginning in 1850. GISS and NCDC both start in 1880. And the satellite data don’t start until December 1978 (for UAH) or January 1979 (for RSS). You can download the data yourself; links to data sources are found here. Because of this, the RSS and UAH data cannot be put on the baseline used by any of the surface-temperature data sets because the satellite data don’t cover those time periods. Of course we can only compare them for those times they all have data. And to put them all on the same scale, we’ll have to use a baseline period which is covered by all.

All 5 data sets cover the period 1979 to the present, although HadCRU hasn’t yet published their results for November 2010, so the period of common coverage is January 1979 to October 2010. Here’s the raw data (each with its own baseline period)


3 01 2015
Dr Bob Rich

Thank you Mark for a very clear and accurate explanation.
To Dave Kimble:
You should re-read Mark’s opening. He is at pains to point out that it doesn’t matter if this is a record year or not. What matters is the steady one way progression. There are always fluctuations, but the average is going up, up, up, in a way that can only be accounted for by human action.

3 01 2015
Dr Bob Rich

Reblogged this on Bobbing Around and commented:
Here is a non-sensational, accurate description of the facts of climate change.

3 01 2015
John Doyle

Actually, using the financial deficit analogy is not a productive approach to any meaningful comparison. Government deficits are a GOOD thing. It means the economy is growing and we all know that’s what we want [ahem!] So his analogy is the opposite of what he’s trying to say.
Re the previous response, why not be scary? are we going to live a lie just because no one has the ticker to say the truth that our civilization is coming to an end. Every civilization has done it, so will we. Already we are deflating as resource availability dries up or gets expensive. People are cutting back and the temporary oil glut shows that demand is down.

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