Featured Research

from universities, journals, and other organizations

Humans, Oceans Shaped North American Climate Over Past 50 Years, NOAA Report Says

Date:
December 29, 2008
Source:
National Oceanic And Atmospheric Administration
Summary:
Greenhouse gases play an important role in North American climate, but differences in regional ocean temperatures may hold a key to predicting future U.S. regional climate changes, according to a new NOAA-led scientific assessment.

Changes in sea-surface temperature patterns likely played an important role in determining differences in U.S. regional temperature trends. They also contributed to large precipitation swings from year to year or decade to decade during the past 50 years.
Credit: NOAA

Greenhouse gases play an important role in North American climate, but differences in regional ocean temperatures may hold a key to predicting future U.S. regional climate changes, according to a new NOAA-led scientific assessment. The assessment is one in a series of synthesis and assessment reports coordinated by the U.S. Climate Change Science Program.

This latest assessment, Reanalysis of Historical Climate Data for Key Atmospheric Features: Implications for Attribution of Causes of Observed Change, describes what has changed—and why—in North America’s climate over the past half century. The assessment addresses the likelihood and extent to which human activity or natural variations have driven surface warming, precipitation, droughts, and floods.

“A major implication of this assessment is that improving predictions of regional sea-surface temperatures will be crucial to predicting climate variability across the U.S. from years to decades, as well as projecting long-term regional climate changes,” said Randall Dole, lead author and a scientist at NOAA’s Earth System Research Laboratory in Boulder, Colo.

Some regional temperatures rose sharply, while others held steady; drought impacts worsened; and precipitation swung widely—all within the continent’s gradually warming climate.

Changes in sea-surface temperature patterns likely played an important role in determining differences in U.S. regional temperature trends. They also contributed to large precipitation swings from year to year or decade to decade during the past 50 years.

While a general trend toward warmer ocean conditions is expected with increasing greenhouse gases, regional differences in sea surface temperature trends can be either natural or human-caused, according to Dole. 

The assessment found that an increase in greenhouse gases is likely responsible for more than half of the average continental warming of 1.6° Fahrenheit observed during the past 50 years.  Greenhouse gases, emitted by fossil fuel burning and natural sources, trap heat in Earth’s atmosphere and warm the surface.

Drought impacts have likely become more severe as surface temperatures warmed, increasing evaporation, reducing soil moisture, and causing other water stresses. The scientists found no long-term trends in where or how often droughts occur or in how much rain or snow has fallen on average each year.

The assessment also describes in detail how climate scientists use enormous amounts of data in a powerful method for examining past climate, called “reanalysis.” Another section illustrates how they systematically probe cause-and-effect relationships to find the most likely cause of a climate trend, a prolonged drought, or an unusually hot year – a process termed ‘attribution’.

In a reanalysis—or retrospective analysis—a high-quality climate record is constructed from past observations collected over a period of time from many different observing systems and combined with a climate model. Reanalysis data, which currently extend as far back as the mid-twentieth century, are important in helping researchers understand how climate evolved.

“Using reanalysis and attribution methods we can now say with more confidence what’s driving some of the extreme climate conditions of the past few years: whether it’s global warming, El Niño, La Niña, or some other pattern,” said NOAA scientist Martin Hoerling, also of the Earth System Research Laboratory and a lead author on the report. “That’s the information policymakers and the public ask for.” Hoerling also heads NOAA’s climate attribution team.


Story Source:

The above story is based on materials provided by National Oceanic And Atmospheric Administration. Note: Materials may be edited for content and length.


Cite This Page:

National Oceanic And Atmospheric Administration. "Humans, Oceans Shaped North American Climate Over Past 50 Years, NOAA Report Says." ScienceDaily. ScienceDaily, 29 December 2008. <www.sciencedaily.com/releases/2008/12/081227230140.htm>.
National Oceanic And Atmospheric Administration. (2008, December 29). Humans, Oceans Shaped North American Climate Over Past 50 Years, NOAA Report Says. ScienceDaily. Retrieved April 17, 2014 from www.sciencedaily.com/releases/2008/12/081227230140.htm
National Oceanic And Atmospheric Administration. "Humans, Oceans Shaped North American Climate Over Past 50 Years, NOAA Report Says." ScienceDaily. www.sciencedaily.com/releases/2008/12/081227230140.htm (accessed April 17, 2014).

Share This



More Earth & Climate News

Thursday, April 17, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

The Great British Farmland Boom

The Great British Farmland Boom

Reuters - Business Video Online (Apr. 17, 2014) — Britain's troubled Co-operative Group is preparing to cash in on nearly 18,000 acres of farmland in one of the biggest UK land sales in decades. As Ivor Bennett reports, the market timing couldn't be better, with farmland prices soaring over 270 percent in the last 10 years. Video provided by Reuters
Powered by NewsLook.com
Small Reactors Could Be Future of Nuclear Energy

Small Reactors Could Be Future of Nuclear Energy

AP (Apr. 17, 2014) — After the Fukushima nuclear disaster, the industry fell under intense scrutiny. Now, small underground nuclear power plants are being considered as the possible future of the nuclear energy. (April 17) Video provided by AP
Powered by NewsLook.com
Change of Diet Helps Crocodile Business

Change of Diet Helps Crocodile Business

Reuters - Business Video Online (Apr. 16, 2014) — Crocodile farming has been a challenge in Zimbabwe in recent years do the economic collapse and the financial crisis. But as Ciara Sutton reports one of Europe's biggest suppliers of skins to the luxury market has come up with an unusual survival strategy - vegetarian food. Video provided by Reuters
Powered by NewsLook.com
How Mt. Everest Helped Scientists Research Diabetes

How Mt. Everest Helped Scientists Research Diabetes

Newsy (Apr. 15, 2014) — British researchers were able to use Mount Everest's low altitudes to study insulin resistance. They hope to find ways to treat diabetes. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins