Rivers, streams cover substantially more of Earth's surface than we thought

June 28, 2018

A new global map of rivers and streams created using satellite data suggests that the global surface area of these bodies of water is about 44% higher than previously thought. Only two studies to date have attempted to quantify the global surface area of rivers and these were based on limited data; yet important and complex chemical exchanges with the atmosphere and biosphere happen at the water-atmosphere interface of rivers. For example, rivers release roughly one-fifth of the carbon dioxide levels emitted by fossil fuel combustion and cement production. Using satellite data, George Allen and Tamlin Pavelsky created one of the most detailed databases of rivers and streams to date, called the Global River Widths from Landsat (GRWL) Database. It quantifies the surface area of rivers greater than 90 kilometers (km) in width. The authors performed a series of calculations to account for smaller rivers, for which less data is available. Collectively, global rivers and streams were estimated to cover roughly 773,000 km2 of Earth's global non-glaciated land surface - tens of thousands of kilometers squared higher than previous estimates. Regionally, the authors report more river surface area coverage in the Arctic (where the impacts of climate change on carbon fluxes are of major concern) than previous estimates have ballparked, and less in Europe, the U.S., and some other economically developed regions. Allen and Pavelsky note that the lower-than-previous estimate of river surface area in many developed areas may suggest large-scale impacts of human modification on river networks, although this hypothesis requires further testing.
-end-


American Association for the Advancement of Science

Related Climate Change Articles from Brightsurf:

Are climate scientists being too cautious when linking extreme weather to climate change?
Climate science has focused on avoiding false alarms when linking extreme events to climate change.

Mysterious climate change
New research findings underline the crucial role that sea ice throughout the Southern Ocean played for atmospheric CO2 in times of rapid climate change in the past.

Mapping the path of climate change
Predicting a major transition, such as climate change, is extremely difficult, but the probabilistic framework developed by the authors is the first step in identifying the path between a shift in two environmental states.

Small change for climate change: Time to increase research funding to save the world
A new study shows that there is a huge disproportion in the level of funding for social science research into the greatest challenge in combating global warming -- how to get individuals and societies to overcome ingrained human habits to make the changes necessary to mitigate climate change.

Sub-national 'climate clubs' could offer key to combating climate change
'Climate clubs' offering membership for sub-national states, in addition to just countries, could speed up progress towards a globally harmonized climate change policy, which in turn offers a way to achieve stronger climate policies in all countries.

Review of Chinese atmospheric science research over the past 70 years: Climate and climate change
Over the past 70 years since the foundation of the People's Republic of China, Chinese scientists have made great contributions to various fields in the research of atmospheric sciences, which attracted worldwide attention.

A CERN for climate change
In a Perspective article appearing in this week's Proceedings of the National Academy of Sciences, Tim Palmer (Oxford University), and Bjorn Stevens (Max Planck Society), critically reflect on the present state of Earth system modelling.

Fairy-wrens change breeding habits to cope with climate change
Warmer temperatures linked to climate change are having a big impact on the breeding habits of one of Australia's most recognisable bird species, according to researchers at The Australian National University (ANU).

Believing in climate change doesn't mean you are preparing for climate change, study finds
Notre Dame researchers found that although coastal homeowners may perceive a worsening of climate change-related hazards, these attitudes are largely unrelated to a homeowner's expectations of actual home damage.

Older forests resist change -- climate change, that is
Older forests in eastern North America are less vulnerable to climate change than younger forests, particularly for carbon storage, timber production, and biodiversity, new research finds.

Read More: Climate Change News and Climate Change Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.