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The global CO2 rise: the facts, Exxon and the favorite denial tricks

Filed under: — stefan @ 25 January 2018

The basic facts about the global increase of CO2 in our atmosphere are clear and established beyond reasonable doubt. Nevertheless, I’ve recently seen some of the old myths peddled by “climate skeptics” pop up again. Are the forests responsible for the CO2 increase? Or volcanoes? Or perhaps the oceans?

Let’s start with a brief overview of the most important data and facts about the increase in the carbon dioxide concentration in the atmosphere:

  1. Since the beginning of industrialization, the CO2 concentration has risen from 280 ppm (the value of the previous millennia of the Holocene) to now 405 ppm.
  2. This increase by 45 percent (or 125 ppm) is completely caused by humans.
  3. The CO2 concentration is thus now already higher than it has been for several million years.
  4. The additional 125 ppm CO2 have a heating effect of 2 watts per square meter of earth surface, due to the well-known greenhouse effect – enough to raise the global temperature by around 1°C until the present.

Fig. 1 Perhaps the most important scientific measurement series of the 20th century: the CO2 concentration of the atmosphere, measured on Mauna Loa in Hawaii. Other stations of the global CO2 measurement network show almost exactly the same; the most important regional variation is the greatly subdued seasonal cycle at stations in the southern hemisphere. This seasonal variation is mainly due to the “inhaling and exhaling” of the forests over the year on the land masses of the northern hemisphere. Source (updated daily): Scripps Institution of Oceanography. More »

Fall AGU 2017

It’s that time of year again. #AGU17 is from Dec 11 to Dec 16 in New Orleans (the traditional venue in San Francisco is undergoing renovations).

As in previous years, there will be extensive live streams from “AGU On Demand” (free, but an online registration is required) of interesting sessions and the keynote lectures from prize-winners and awardees.

Some potential highlights will be Dan Rather, Baba Brinkman, and Joanna Morgan. The E-lightning sessions are already filled with posters covering many aspects of AGU science. Clara Deser, Bjorn Stevens, David Neelin, Linda Mearns and Thomas Stocker are giving some the key climate-related named lectures. The Tyndall Lecture by Jim Fleming might also be of interest.

As usual there are plenty of sessions devoted to public affairs and science communication, including one focused on the use of humour in #scicomm (on Friday at 4pm to encourage people to stay to the end I imagine), and a workshop on Tuesday (joint with the ACLU and CSLDF) on legal issues for scientist activists and advocates.

AGU is also a great place to apply for jobs, get free legal advice, mingle, and network.

A couple of us will be there – and we might find time to post on anything interesting we see. If any readers spot us, say hi!

Impressions from the European Meteorological Society’s annual meeting in Dublin 

Filed under: — rasmus @ 14 September 2017

The 2017 annual assembly of the European Meteorological Society (EMS) had a new set-up with a plenary keynote each morning. I though some of these keynotes were very interesting. There was a talk by Florence Rabier from the European Centre for Medium-range Weather Forecasts (ECMWF), who presented the story of ensemble forecasting. Keith Seitter, the executive director of the American Meteorological Society (AMS), talked about the engagement with the society on the Wednesday.

The Helix at DCU was the main venue of #EMS2017

More »

Joy plots for climate change

Filed under: — gavin @ 22 July 2017

This is joy as in ‘Joy Division’, not as in actual fun.

Many of you will be familiar with the iconic cover of Joy Division’s Unknown Pleasures album, but maybe fewer will know that it’s a plot of signals from a pulsar (check out this Scientific American article on the history). The length of the line is matched to the frequency of the pulsing so that successive pulses are plotted almost on top of each other. For many years this kind of plot did not have a well-known designation until, in fact, April this year:

So “joy plots” it is.

More »

The climate has always changed. What do you conclude?

Filed under: — stefan @ 20 July 2017

Probably everyone has heard this argument, presented as objection against the findings of climate scientists on global warming: “The climate has always changed!” And it is true: climate has changed even before humans began to burn fossil fuels. So what can we conclude from that?

A quick quiz

Do you conclude…

(1) that humans cannot change the climate?

(2) that we do not know whether humans are to blame for global warming?

(3) that global warming will not have any severe consequences?

(4) that we cannot stop global warming? More »

What do you need to know about climate?

What do you need to know about climate in order to be in the best position to adapt to future change? This question was discussed in a European workshop on Copernicus climate services during a heatwave in Barcelona, Spain (June 12-14).

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Snow Water Ice and Water and Adaptive Actions for a Changing Arctic

The Arctic is changing fast, and the Arctic Council recently commissioned the Arctic Monitoring and Assessment Programme (AMAP) to write two new reports on the state of the Arctic cryosphere (snow, water, and ice) and how the people and the ecosystems in the Arctic can live with these changes.

The two reports have now just been published and are called Snow Water Ice and Permafrost in the Arctic Update (SWIPA-update) and Adaptive Actions for a Changing Arctic (AACA).

More »

Fake news, hacked mail, alternative facts – that’s old hat for climate scientists

Distortion? False information? Conspiracy theories? Hacked email? Climate scientists have known all this for decades. What can be learned from their rich experience with climate propaganda.

The world is slowly waking up. “Post-truth” was declared the word of the year 2016 by the Oxford Dictionaries. Finally, people start to widely appreciate how dangerous the epidemic of fake news is for democracy.

Stir up hate, destroy discourse, make insane claims until no one can distinguish the most bizarre absurdity from the truth any more.

Thus the Austrian author Robert Misik aptly describes the strategy of right-wing populists.

Some call it “alternative facts”. (Those are the convenient alternative to true facts.) Let’s simply call it propaganda. More »

New report: Climate change, impacts and vulnerability in Europe 2016

Filed under: — rasmus @ 6 February 2017

Another climate report is out – what’s new? Many of the previous reports have presented updated status on the climate and familiar topics such as temperature, precipitation, ice, snow, wind, and storm activities.

The latest report Climate change, impacts and vulnerability in Europe 2016 from the European Environment Agency (EEA) also includes an assessment of hail, a weather phenomenon that is often associated with lightening (a previous report from EASAC from 2013 also covers hail).

Usually, there has not been a lot of information about hail, but that is improving. Still, the jury is still out when it comes to hail and climate change:

Despite improvements in data availability, trends and projections of hail events are still uncertain.

More »

The NASA data conspiracy theory and the cold sun

When climate deniers are desperate because the measurements don’t fit their claims, some of them take the final straw: they try to deny and discredit the data.

The years 2014 and 2015 reached new records in the global temperature, and 2016 has done so again. Some don’t like this because it doesn’t fit their political message, so they try to spread doubt about the observational records of global surface temperatures. A favorite target are the adjustments that occur as these observational records are gradually being vetted and improved by adding new data and eliminating artifacts that arise e.g. from changing measurement practices or the urban heat island effect. More about this is explained in this blog article by Victor Venema from Bonn University, a leading expert on homogenization of climate data. And of course the new paper by Hausfather et al, that made quite a bit of news recently, documents how meticulously scientists work to eliminate bias in sea surface temperature data, in this case arising from a changing proportion of ship versus buoy observations. More »