Winter Storms and Climate Change, in English
There are few good explanations of how strong winter storms can exist in a warming world. Most explanations, I find, take a defensive posture against climate deniers. I think science writers should just stick to the science, and move away from addressing deniers. Or at least stop weaving denial into articles. The main points get buried, the author looks defensive, and the reader is left exasperated. Climate Communication has a pretty darn good explanation of how winter storms work, and why they could be getting stronger. They stick to the science, and avoid the fray.
See more at: www.climatecommunication.org
Climate change is fueling an increase in the intensity and snowfall of winter storms. The atmosphere now holds more moisture, and that in turns drives heavier than normal precipitation, including heavier snowfall in the appropriate conditions.1
Heavy snowfall and snowstorm frequency have increased in many northern parts of the United States.2 The heavier-than-normal snowfalls recently observed in the Midwest and Northeast United States are consistent with climate model projections. In contrast, the South and lower Midwest saw reduced snowstorm frequency during the last century.3 Overall snow cover has decreased in the Northern Hemisphere, due in part to higher temperatures that shorten the time snow spends on the ground.
Snowstorms Shift Northward in the Northern Hemisphere
The regional pattern of fewer snowstorms in the southern United States and more in the North corresponds to a similar northward shift of cold-season storms in the entire Northern Hemisphere over the past 50 years. Mid-latitude storms have decreased in frequency (e.g., in the United States overall) while high-latitude storm activity has increased (e.g., in Canada).4 It is likely that human influence contributed to these changes.5
How did they know the global average temperature in 1880? -a curious science follower
A question by Anonymous
Great question! Simplest answer: thermometers. Simple instruments such as thermometers and barometers have been used for centuries. Governments began to collect data from these instruments beginning in the early 1700s. (There are early data sets, but these focused on local or route specific locations rather than globally. For example, shipping companies collected ocean temperatures during the 1600s along specific routes to report conditions to insurance companies.).
The old-school instruments were placed in locations all around the world (locations ranged from trees, church steeples and clocks, tall poles, cliff faces, to just stuck in the ground). Governments collected the temperatures typically for military, farming, and shipping purposes.
The U.S. Weather Bureau, established in 1735, was sporadically managed by a few individual states (rather than the Federal Government). The bureau collected local information - not global.
In 1814, the U.S. Federal Government established the U.S.’s first nation wide weather service. Army doctors and ‘war’ hospitals were instructed to keep diaries of local weather. But, again, this was not a global system.
In 1870, President Ulysses Grant established the U.S. National Weather Service (NWS):
The beginning of the National Weather Service we know today started on February 9th, 1870, when President Ulysses S. Grant signed a joint resolution of Congress authorizing the Secretary of War to establish a national weather service. This resolution required the Secretary of War:
“to provide for taking meteorological observations at the military stations in the interior of the continent and at other points in the States and Territories…and for giving notice on the northern (Great) Lakes and on the seacoast by magnetic telegraph and marine signals, of the approach and force of storms”
After much thought and consideration, it was decided that this agency would be placed under the Secretary of War because military discipline would probably secure the greatest promptness, regularity, and accuracy in the required observations. Via NOAA
The NWS worked internationally. It collected data from its own instruments, and also from data shared by other countries, such as Denmark, France, India, and the U.K.
The NWS’s information was collected over time, and digitized into big data sets. These sets are used today!
The chart below shows temperature data over 1,000 years. (NOTE: This chart is from wikipedia entry “Temperature record of the past 1,000 years." I do not endorse this chart. I’m posting for illustrative purposes to help answer anon’s question about records from 1880).
Note the black line (far right). It shows collected instrument data from 1850 to 2004. Data prior to 1850 is collected by climate proxies.
Finally, if you’re interested, you can read about the weather data sets collected in the 1850s. This paper, Uncertainty estimates in regional and global observed temperature changes: a new dataset from 1850, covers the history of that data, as well as issues with using it in modern climate models.
Hope that helps!