Extreme Event Attribution

Whenever a cataclysmic weather event occurs—like Hurricane Harvey right now—there’s usually a heated political argument over whether or not it can be blamed on climate change. It turns out that there’s a field of research dedicated to assessing whether extreme weather can be attributed to climate change: it’s called extreme event attribution. There have been more than 140 peer-reviewed attribution studies of extreme weather events around the globe, which Carbon Brief has mapped here.

Carbon Brief’s analysis suggests 63% of all extreme weather events studied to date were made more likely or more severe by human-caused climate change. Heatwaves account for nearly half of such events (46%), droughts make up 21% and heavy rainfall or floods account for 14%.

[Benjamin Hennig]

FEMA Flood Maps Don’t Account for Future Sea Level Rise

NPR last month, reporting on a problem with FEMA’s flood insurance maps: they’re not keeping up with reality. “FEMA’s insurance maps are based on past patterns of flooding. Future sea level rise—which is expected to create new, bigger flood zones—is not factored in. So some communities are doing the mapping themselves. Like Annapolis, the state capital of Maryland.” [Leventhal]

Mapping Arctic Warming

At All Over the Map, Betsy Mason posts 11 Ways to See How Climate Change Is Imperilling the Arctic, a collection of maps and infographics depicting several different indicators of global warming, including sea ice extent, atmospheric temperatures, growing season, polar bear populations, as well as projected shipping routes for an ice-free Arctic Ocean.

NASA Earth Observatory

Meanwhile, NASA Earth Observatory points—while it still can—to a study mapping the extent of existing and potential thermokarst (thawed permafrost) landscapes. On the Earth Observatory maps (see North America, above), “[t]he different colors reflect the types of landscapes—wetlands, lakes, hillslopes, etc.—where thermokarst is likely to be found today and where it is most likely to form in the future.”

Previously: Mapping Arctic Sea IceMapping the Thaw.

Mapping Arctic Sea Ice


Something’s going on in the Arctic. As the Washington Post reported last month, the Arctic Ocean was far, far warmer than normal—about 20 degrees Celsius higher than average. (Meanwhile, the air over Sibera is at record cold levels.) According to the Post, the higher temperatures are the result of record low amounts of thinning sea ice, as well as warm air being brought north by an increasingly errant jet stream.

NASA has been tracking sea ice levels and thickness by looking at the age of the ice in the sea ice cap. The video above shows “how Arctic sea ice has been growing and shrinking, spinning, melting in place, and drifting out of the Arctic for the past three decades. The age of the ice is represented in shades of blue-gray to white, with the brightest whites representing the oldest ice.”

The ESA reports that their CryoSat satellite “has found that the Arctic has one of the lowest volumes of sea ice of any November, matching record lows in 2011 and 2012.” The animated GIF below shows the change in November sea ice from 2011 to 2016, as observed by CryoSat.


Migrations in Motion


Migrations in Motion models the average directions wildlife will need to move in order to survive the effects of climate change. As Canadian Geographic explains, “As climate change disrupts habitats, researchers believe wildlife will instinctively migrate to higher elevations and latitudes, but for many species, that will mean navigating around, over or through human settlements and infrastructure.” The map, the design of which is modeled on the hint.fm wind map, covers both North and South America and does not purport to model the path of individual species; rather it’s an average based on computer modelling.

Hazard Maps of Yukon Communities

Old Crow Landscape Hazard Risk Map (detail).
Old Crow Landscape Hazard Risk Map (detail).

Several Yukon communities are built on permafrost. In the context of climate change, that’s something of a problem. CBC News reports on a six-year research project that has produced hazard maps of seven Yukon communities; the maps evaluate the risk to future development from permafrost melting, flooding and ground instability. [CCA]

Oceania: The Truncated Continent


In “Cartographic ethics: Oceania, the truncated continent,” Dietmar Offenhuber complains about world maps of climate change that obscure the region of the world most affected by it: Oceania. It’s an important point both in specific and in general, as he goes on to say:

Oceania is mostly an invisible continent: its islands, islets, and atolls being too small to be printed on most world maps. On the outer fringes of most world maps, its territories are cropped or covered by a legend. With of our example, the world ends just after New Zealand, and the legend covers eastern parts of French Polynesia.

The thoughtless use of Mercator projections in world maps is generally frowned upon, but truncating the lobes of projections such as Mollweide and Robinson is just as bad. But even without such mistakes, all political maps struggle with a conflict of intent: on the one hand, accurate representation of territory, on the other hand, the appropriate representation of populations.

To get a better picture of Oceania, I made a simple map of all named islands and atolls, described in the remainder of this post.

(See map above.) [Boing Boing]

Surface Temperatures Warmest Since 1880

According to analyses by NASA and NOAA scientists, 2015 was the warmest year on record, with average surface temperatures the highest they’ve been since 1880. The above video shows the long-term warming trend since 1880 as a five-year rolling average. The baseline average is from 1951 to 1980; orange colours are warmer than that average, blue colours cooler. (Credit: GSFC Scientific Visualization Studio.)

Mapping the Thaw

Scientists have been tracking seasonal freeze-thaw patterns for 30 years. This map, produced from data collected by NASA’s Soil Moisture Active Passive satellite, “shows the freeze-thaw status of areas north of 45 degrees latitude on March 5, 2015, as spring approached. Frozen land is blue; thawed land is pink. The measurement is possible because frozen water forms crystalline structures that can be detected by satellites.” NASA Earth Observatory.