Climate Signals and “Demystifying Climate Models”: Two Great New Resources

Whether it be in media coverage or in statements by politicians, the connections between our warming planet and extreme weather events are too often ignored or downplayed (or sometimes overplayed). Those who want to learn more about the global climate models that bolster our understanding of past, recent, and future change can face a seemingly impenetrable wall of jargon, formulas, and technical terms. Where can you quickly find the context to put a breaking weather event into a solid climate perspective, or to get a handle on how global climate models work? Two excellent resources are now available to meet both of these needs.

A new tool for connecting the dots between extreme events and climate change
Debuting in beta form last month, the Climate Signals website--created by the nonprofit organization Climate Nexus--offers a quick and handy way to explore the climate change elements that are most pertinent to a given extreme event. The site’s main page allows you to click on a U.S. map that shows ongoing, recent, and significant past events, including heat waves, floods, and other weather disasters as well as ecosystem shocks such as wildfire and high-latitude ice loss. Click on an event and you get a brief summary, together with a curated list of media reports and relevant research findings. Each event also features a schematic “tree” that shows the chain of physical and social processes running from greenhouse gases to the event. Some of the trees are richly branched; others have as little as a single connection. Rather than showing the relative strength of the various factors compared to each other, or to natural variability, the trees are intended simply to show which aspects of climate change are most relevant to a given event. There is a “dashed line” branch used for links that are not yet firmly supported by observations but are consistent with model projections.


Figure 1. The schematic “tree” used to show connections between increased greenhouse gas emissions from human activity (left) and the torrential rains and severe flooding that struck northern Louisiana and nearby areas in early March 2016. More than 20 inches of rain fell in a four-day period in some areas. The dashed line indicates a link that is found in modeling but not yet fully supported by observations. The site notes: “This diagram does not quantify the relative strength of each factor, nor does it illustrate the natural factors that often shape extreme events, including natural variability and regular circulation changes.” Image credit: Climate Signals.


For journalists, policy makers, or any other interested parties delving into such high-profile events as Hurricane Sandy or the multi-year California drought, Climate Signals will serve as a convenient and easy-to-navigate starting point. Peer-reviewed attribution studies--which are referenced throughout the Climate Signals site--are the place to dig deeper when researching how much a given facet of climate change may have influenced a particular extreme event. We also found that the Real Time Data page--which contains over 50 links to various websites on current extreme temperatures, rainfall, storms, drought, fire, sea level, insect activity, snow, and ice--is a fantastic resource for researching the real-time impacts of extreme weather. The Climate Signals team is now seeking feedback on its beta site. 



Ricky Rood has a book out!
As those of you who follow wunderground climate change blogger Dr. Ricky Rood know, Ricky has bravely forayed into the world of long-form publication with his first-ever book: Demystifying Climate Models: A Users Guide to Earth System Models. A free electronic version is available as well. First author Dr. Andrew Gettelman (a climate scientist and expert on aerosols and cloud microphysics who is based at NCAR, the National Center for Atmospheric Research) and Ricky have written a book aimed at scientists and engineers in fields such as ecosystems, water resources, and urban planning who need quantitative climate change information for decision-making. By understanding climate models and their uncertainties, the reader should become a more competent interpreter or translator of climate model output. Although the book delves into many aspects of how climate models work, it is not a technical manual: there are virtually no equations, and the writing is conversational and accessible.

The book is full of enlightening examples of the strengths and weaknesses of climate models. Here's one example from the chapter titled “Results of Current Models” that we found valuable: "There is no explicit law for how much precipitation will increase, but most model simulations indicate that the increase is about 2% per degree centigrade of warming. Precipitation is a classic case where some aspects of the impacts of climate change are well known, and some are much more uncertain. As noted briefly in Chap. 10, as the spatial scale of interest decreases, the large-scale constraints fall away, and potential model structural errors start to become larger. While models agree on the sign and even some of the magnitude of global trends, they do not agree on the magnitude (even the magnitude of global changes), and particularly on what happens in different regions."

Demystifying Climate Models does a tremendous job of filling the gap between highly technical textbooks and more superficial descriptions of climate modeling. Even better, anyone can download a PDF or ePub version at no cost via the book’s website. A hardcover print version is also available at a $59.99 list price, which is quite reasonable for a book of this quality and depth. The book’s production was partially supported by NCAR.

Quiet time in the tropics; a hot weekend ahead for the States
There are no tropical cyclones being tracked anywhere on Earth this morning, but there is plenty of heat around, with some impressive records being set in some far-flung locations. A new record in Greenland for the month of June was set on Thursday when the airport at Nuuk (Mittarfik Nuuk) soared to 24.7°C. Much of the central and eastern United States will be cooking this weekend, with temperatures soaring well above 90°F as far north as Minnesota and the Dakotas. We'll take a closer look at national and global heat next week. In the meantime, have a great weekend, and stay cool, everyone!

Jeff Masters and Bob Henson