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Do regional climate models add value compared to global models?

2016-05-20 10.08.17

Global climate models (GCM) are designed to simulate earth’s climate over the entire planet, but they have a limitation when it comes to describing local details due to heavy computational demands. There is a nice TED talk by Gavin that explains how climate models work.

We need to apply downscaling to compute the local details. Downscaling may be done through empirical-statistical downscaling (ESD) or regional climate models (RCMs) with a much finer grid. Both take the crude (low-resolution) solution provided by the GCMs and include finer topographical details (boundary conditions) to calculate more detailed information. However, does more details translate to a better representation of the world?

The question of “added value” was an important topic at the International Conference on Regional Climate conference hosted by CORDEX of the World Climate Research Programme (WCRP). The take-home message was mixed on whether RCMs provide a better description of local climatic conditions than the coarser GCMs.

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What is the best description of the greenhouse effect?

Filed under: — rasmus @ 12 February 2016

What exactly is the greenhouse effect? And what does it look like if we view it from a new angle? Of course, we know the answer, and Raymond Pierrehumbert has written an excellent paper about it (Infrared radiation and planetary temperature). Computer code used in climate models contain all the details.

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Filed under: — rasmus @ 9 February 2016

Ross McKitrick was so upset about a paper ‘Learning from mistakes in climate research(Benestad et al., 2015) that he has written a letter of complaint and asked for immediate retraction of the pages discussing his work.

This is an unusual step in science, as most disagreements and debate involve a comment or a response to the original article. The exchange of views, then, provides perspectives from different angles and may enhance the understanding of the problem. This is part of a learning process.

Responding to McKitrick’s letter, however, is a new opportunity to explain some basic statistics, and it’s excellent to have some real and clear-cut examples for this purpose.

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  1. R.E. Benestad, D. Nuccitelli, S. Lewandowsky, K. Hayhoe, H.O. Hygen, R. van Dorland, and J. Cook, "Learning from mistakes in climate research", Theoretical and Applied Climatology, vol. 126, pp. 699-703, 2015.

Climate change is coming to a place near you

What are the local consequences of a continued global warming? And what kind of future climate can you expect for you children? Do we expect more extreme events, and will a global warming affect the statistics of storms? Another question is how the local changes matters for local communities and the ecosystem.

It may be contrary to most people’s impression. We have a clearer picture of future climate changes on a global scale than of the local consequences associated with a global warming. And we know why.

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Let’s learn from mistakes

Filed under: — rasmus @ 23 August 2015

The publication ‘Learning from mistakes in climate research’ is the result of a long-winded story with a number of surprises. At least to me.

I have decided to share this story with our readers, since it in some aspects is closely linked with RealClimate.

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