It’s 20 years since we started blogging on climate here on RealClimate (December 10, 2004). We wanted to counter disinformation about climate change that was spreading through various campaigns. In those days it was an unusual move that prompted a welcome from Nature.
[Read more…] about Twenty years of blogging in hindsight
About rasmus
2023 appears to follow an upward trend in the North Atlantic/Caribbean named tropical cyclone count
This year’s (2023) tropical cyclone season in the North Atlantic and Caribbean witnessed a relatively high number of named tropical cyclones: 20. In spite of the current El Niño, which tends to give lower numbers. But it appears to follow a historical trend for named tropical cyclones with an increasing number over time.
The curve presented above is an update of the analysis presented in 2020 and posted here on RealClimate.
[Read more…] about 2023 appears to follow an upward trend in the North Atlantic/Caribbean named tropical cyclone countReferences
- R.E. Benestad, "On tropical cyclone frequency and the warm pool area", Natural Hazards and Earth System Sciences, vol. 9, pp. 635-645, 2009. http://dx.doi.org/10.5194/nhess-9-635-2009
A distraction due to errors, misunderstanding and misguided Norwegian statistics
A friend asked me if a discussion paper published on Statistics Norway’s website, ‘To what extent are temperature levels changing due to greenhouse gas emissions?’, was purposely timed for the next climate summit (COP28). I don’t know the answer to his question.
[Read more…] about A distraction due to errors, misunderstanding and misguided Norwegian statisticsThe 5th International Conference on Regional Climate
The fifth international conference on regional climate (ICRC 2023), organised by World Climate Research Programme’s (WCRP) coordinated downscaling experiment (CORDEX), has just completed. It was a hybrid on-site/online conference with hubs in both Trieste/Italy (hosted by the International Centre on Theoretical Physics, ICTP) and Pune/India.
The hybrid set-up, with video links between the two hubs and digital attendence through zoom, was a change from previous ICRCs held in ICTP (2011), Brussels (2013), Stockholm (2016), and Beijing (2019). It worked impressively well, and the CORDEX ICRC 2023 streaming is available from the WCRP CORDEX YouTube channel.
It seems as an eternity since the previous ICRC before the COVID pandemic, so I was curious to see how things have progressed since then. It was also interesting to compare my impressions from this conference with my blog posts here on RealClimate from the first ICRC in Trieste, the second in Brussels, the third ICRC in Stockholm, I see that questions concerning uncertainty and added value are still being debated.
Old habits
Media awareness about global warming and climate change has grown fairly steadily since 2004. My impression is that journalists today tend to possess a higher climate literacy than before. This increasing awareness and improved knowledge is encouraging, but there are also some common interpretations which could be more nuanced. Here are two examples, polar amplification and extreme rainfall.
[Read more…] about Old habitsArea-based global hydro-climatological indicators
The World Meteorological Organisation (WMO) Global Climate Observing System (GCOS) and Copernicus Climate Change Services (C3S) both provide sets of global climate statistics to summarise the state of Earth’s climate. They are indeed valuable indicators for the global or regional mean temperature, greenhouse gas concentrations, both ice volume and area, ocean heat, acidification, and the global sea level.
Still, I find it surprising that the set does not include any statistics on the global hydrological cycle, relevant to rainfall patterns and droughts. Two obvious global hydro-climatological indicators are the total mass of water falling on Earth’s surface each day P and the fraction of Earth’s surface area on which it falls Ap.
[Read more…] about Area-based global hydro-climatological indicatorsEvaluation of GCM simulations with a regional focus.
Do the global climate models (GCMs) we use for describing future climate change really capture the change and variations in the region that we want to study? There are widely used tools for evaluating global climate models, such as the ESMValTool, but they don’t provide the answers that I seek.
I use GCMs to provide information about large-scale conditions, processes and phenomena in the atmosphere that I can use as predictors in downscaling future climate projections. I also want to know whether the ensemble of GCM simulations that I use provides representative statistics of the actual regional climate I’m interested in.
[Read more…] about Evaluation of GCM simulations with a regional focus.The summary for policymakers of the Intergovernmental Panel on Climate Change sixth assessment reports synthesis
The summary for policymakers of the Intergovernmental Panel on Climate Change (IPCC) sixth synthesis report was released on March 20th (available online as a PDF). There is a recording of the IPCC Press Conference – Climate Change 2023: Synthesis Report for those who are interested in watching an awkward release of the report.
It strikes me that the IPCC perhaps assumes that everyone is climate literate and are up to speed on climate change. While many journalists clearly got the message, expressed through news reports though e.g. the Guardian and Washington Post, I doubt that relevant leaders were swayed. One problem may be that journalists do not carry as much weight as scientists.
[Read more…] about The summary for policymakers of the Intergovernmental Panel on Climate Change sixth assessment reports synthesisThe established ground and new ideas
Science is naturally conservative and the scepticism to new ideas ensures high scientific quality. We have more confidence when different scholars arrive at the same conclusion independently of each other. But scientific research also brings about discoveries and innovations, and it typically takes time for such new understanding to receive acknowledgement and acceptance. In the meanwhile, it’s uncertain whether they really represent progress or if they are misconceived ideas. Sometimes we can shed more light on new ideas through scientific discussions.
[Read more…] about The established ground and new ideasSerious mistakes found in recent paper by Connolly et al.
Guest post by Mark Richardson who is a Research Scientist in the Aerosol and Clouds Group at NASA’s Jet Propulsion Laboratory, California Institute of Technology. All opinions expressed are his own and do not in any way represent those of NASA, JPL or Caltech.
Should scientists choose to believe provably false things? Even though that would mean more inclusive debates with a wider range of opinions, our recent paper Richardson & Benestad (2022) argues no: “instead of repeating errors, they should be acknowledged and corrected so that the debate can focus on areas of legitimate scientific uncertainty”. We were responding to Connolly et al., who suggested that maybe the Sun caused “most” of the warming in “recent decades” based on a simple maths mistake.
[Read more…] about Serious mistakes found in recent paper by Connolly et al.References
- M.T. Richardson, and R.E. Benestad, "Erroneous use of Statistics behind Claims of a Major Solar Role in Recent Warming", Research in Astronomy and Astrophysics, vol. 22, pp. 125008, 2022. http://dx.doi.org/10.1088/1674-4527/ac981c