Northern Hemisphere getting warmer over a larger area due to global warming, report

February 9, 2006
Earth from space

The temperature of the northern hemisphere has increased over a larger area in the last century than at any time in the past millennium a report published in Science reveals this week.

The study finds that the number of “hot spots” has increased dramatically in the Northern Hemisphere in the last century compared to the past 1200 years – adding to the growing evidence of wide-scale global warming.

Dr Tim Osborn and Prof Keith Briffa, of the Climatic Research Unit team at the University of East Anglia, analyzed thermometer measurements of temperature from 1856 onwards to establish the spatial extent of recent warming, and compared it with evidence from as far back as AD 800 (from tree rings, ice cores and shells).

The study found evidence for periods of significant warmth (890 – 1170) in the Northern Hemisphere during medieval times and for clearly colder periods (1580 – 1850) during the so-called “Little Ice Age”.

Their key conclusion was that the 20th century stands out as having unusually widespread warmth, compared to all of the natural warming and cooling episodes during the past 1,200 years.

The research team gathered climate change data from a number of regions in the Northern Hemisphere especially:

Long life evergreen trees growing in Scandinavia, Siberia and the Rockies, which had been cored to reveal the patterns of wide and narrow tree rings over time – wider rings relating to warmer temperatures.

Ice from cores drilled in the Greenland ice sheets revealed which years were warmer than others by the chemical composition of the ice.

They also used a record developed from diaries of people living in the Netherlands and Belgium over the past 750 years that revealed for example the years when the canals froze.

Source: University of East Anglia

Explore further: Unusual red arcs spotted on icy Saturn moon Tethys

Related Stories

Unusual red arcs spotted on icy Saturn moon Tethys

July 30, 2015

Like graffiti sprayed by an unknown artist, unexplained arc-shaped, reddish streaks are visible on the surface of Saturn's icy moon Tethys in new, enhanced-color images from NASA's Cassini spacecraft.

'Bathtub rings' suggest Titan's dynamic seas

July 28, 2015

Saturn's moon, Titan, is the only object in the Solar System other than Earth known to have liquid on its surface. While most of the lakes are found around the poles, the dry regions near the equator contain signs of evaporated ...

Researchers show new Ice Age may begin by 2030

July 17, 2015

The arrival of intense cold similar to the weather that raged during the "Little Ice Age", which froze the world during the 17th century and in the beginning of the 18th century, is expected in the years 2030 to 2040. These ...

Sun's activity controls Greenland temperatures

July 16, 2015

The sun's activity could be affecting a key ocean circulation mechanism that plays an important role in regulating Greenland's climate, according to a new study. The phenomenon could be partially responsible for cool temperatures ...

Volcanic eruptions slow down climate change - temporarily

July 7, 2015

Although global concentration of greenhouse gases in the atmosphere has continuously increased over the past decade, the mean global surface temperature has not followed the same path. A team of international reseachers, ...

Recommended for you

A novel toxin for M. tuberculosis

August 4, 2015

Despite 132 years of study, no toxin had ever been found for the deadly pathogen Mycobacterium tuberculosis, which infects 9 million people a year and kills more than 1 million.

Fast times and hot spots in plasmonic nanostructures

August 4, 2015

The ability to control the time-resolved optical responses of hybrid plasmonic nanostructures was demonstrated by a team led by scientists in the Nanophotonics Group at the Center for Nanoscale Materials including collaborators ...

Will SETI's unprecedented new program finally find E.T.?

August 4, 2015

Stephen Hawking, Frank Drake and dozens of journalists gathered at the Royal Society in London last week to hear astronomers announce a ground-breaking new project to search for intelligent extraterrestrial life called "Breakthrough ...

New biosensors for managing microbial 'workers'

August 4, 2015

Super productive factories of the future could employ fleets of genetically engineered bacterial cells, such as common E. coli, to produce valuable chemical commodities in an environmentally friendly way. By leveraging their ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.