Sportsentusiasternes site no 1

Oddset har designet et sit til rigtige drengerøve: Et site der spotter kvinders manglende evne til at indse vigtigheden i at indtage store mængder kød, øl og fodbold fra sofaen magelighed en hel weekend uden afbrydelser. I en konkurrence som de har stablet på benene, kan du i hovedpræmie blandt andet få en pizza opkaldt efter dig selv!
www.derersaamegetkvinderikkeforstaar.dk

The Last 2,000 Years

During the last 2,000 years, the climate has been relatively stable. Scientists have identified three departures from this stability, known as the Medieval Climate Anomaly (also referred to as the Medieval Warm Period), the Little Ice Age and the Industrial Era:

The Medieval Climate Anomaly: Between roughly 900 and 1300 AD, evidence suggests Europe, Greenland and Asia experienced relative warmth. While historical accounts and other evidence document the warmth that occurred in some regions, the geographical extent, magnitude and timing of the warmth during this period is uncertain (NRC, 2006). The American West experienced very dry conditions around this time.

The Little Ice Age: A wide variety of evidence supports the global existence of a "Little Ice Age" (this was not a true "ice age" since major ice sheets did not develop) between about 1500 and 1850 (NRC, 2006). Average temperatures were possibly up to 2ºF colder than today, but varied by region.

The Industrial Era: An additional warm period has emerged in the last 100 years, coinciding with substantially increasing emissions of greenhouse gases from human activities.

Håndværker - colic-help - skateboard - mystic - grishnach

bloggerwave

Bloggerwave is a new concept that I have run into. You can EARN MONEY WITH YOUR BLOG!
Here is the deal: Big companies are willing to pay you money for writing about their concept or products on your blog and put in a few links in the tekst. By been a member of Bloggerwave the companies can find and pay you. The job is EASY: typically you will paid around USD 10,- for writing at least 50 words. It doesn´t get any better than this!
Bloggerwave

Abrupt or rapid climate changes

Abrupt or rapid climate changes tend to frequently accompany transitions between glacial and interglacial periods (and vice versa). For example, a significant part of the Northern Hemisphere (particularly around Greenland) may have experienced warming ratesof 14-28ºF over several decades during and after the most recent ice age (IPCC, 2007).

While abrupt climate changes have occurred throughout the Earth's history, human civilization arose during a period of relative climate stability.

Håndværker - colic-help - skateboard - nano - superbad

Interglacial climates

Below: This graphic shows the height of the Greenland ice sheet at present (left) and during the last interglacial (about 130,000 years ago), as simulated by the NCAR-based Community Climate System Model coupled with an ice-sheet model. (Illustration courtesy Bette Otto-Bliesner, NCAR.)

Interglacial climates (such as the present) tend to be more stable than cooler, glacial climates. For example, the climate during the current and previous interglacials (known as the Holocene and Eemian interglacials) has been more stable than the most recent glacial period (known as the Last Glacial Maximum). This glacial period was characterized by a long string of widespread, large and abrupt climate changes (NRC, 2002).

Håndværker - colic-help - skateboard - solar - game

Changes in ocean currents:

The heating or cooling of the Earth's surface can cause changes in ocean currents. Because ocean currents play a significant role in distributing heat around the Earth, changes in these currents can bring about significant changes in climate from region to region.

Håndværker - colic-help - skateboard - dali - fart

Rates of Change:

Studies of the Earth's previous climate suggest periods of stability as well as periods of rapid change. Recent climate research suggests:

Håndværker - colic-help - skateboard - bang - area51

Changes in greenhouse gas concentrations:

The heating or cooling of the Earth's surface can cause changes in greenhouse gas concentrations. For example, when global temperatures become warmer, carbon dioxide is released from the oceans. When changes in the Earth's orbit trigger a warm (or interglacial) period, increasing concentrations of carbon dioxide may amplify the warming by enhancing the greenhouse effect. When temperatures become cooler, CO2 enters the ocean and contributes to additional cooling. During at least the last 650,000 years, CO2 levels have tended to track the glacial cycles (IPCC, 2007). That is, during warm interglacial periods, CO2 levels have been high and during cool glacial periods, CO2 levels have been low (see Figure).

Figure: Fluctuations in temperature (red line) and in the atmospheric concentration of carbon dioxide (yellow) over the past 649,000 years. The vertical red bar at the end is the increase in atmospheric carbon dioxide levels over the past two centuries and before 2007.

Håndværker - colic-help - skateboard - invest - ruth

climate change drivers

These climate change “drivers” often trigger additional changes or “feedbacks” within the climate system that can amplify or dampen the climate's initial response to them (whether the response is warming or cooling). For example:

Håndværker - colic-help - skateboard - board - obesity - rfp

Carbon dioxide emissions:

Volcanoes also emit carbon dioxide (CO2), a greenhouse gas, which has a warming effect. For about two-thirds of the last 400 million years, geologic evidence suggests CO2 levels and temperatures were considerably higher than present. One theory is that volcanic eruptions from rapid sea floor spreading elevated CO2 concentrations, enhancing the greenhouse effect and raising temperatures. However, the evidence for this theory is not conclusive and there are alternative explanations for historic CO2 levels (NRC, 2005). While volcanoes may have raised pre-historic CO2 levels and temperatures, according to the USGS Volcano Hazards Program, human activities now emit 150 times as much CO2 as volcanoes (whose emissions are relatively modest compared to some earlier times).

Håndværker - colic-help - skateboard - anorexia - poverty

Aerosol emissions:

Volcanic aerosols tend to block sunlight and contribute to short term cooling. Aerosols do not produce long-term change because they leave the atmosphere not long after they are emitted. According to the United States Geological Survey (USGS), the eruption of the Tambora Volcano in Indonesia in 1815 lowered global temperatures by as much as 5ºF and historical accounts in New England describe 1816 as “the year without a summer.”

Håndværker - colic-help - skateboard - lovsang - hex

Volcanic eruptions:

Volcanoes can affect the climate because they can emit aerosols and carbon dioxide into the atmosphere.

See the differenties next.

Håndværker - colic-help - skateboard - blood red throne - megabordfodbold

Changes in the sun's intensity:

Changes occurring within (or inside) the sun can affect the intensity of the sunlight that reaches the Earth's surface. The intensity of the sunlight can cause either warming (for stronger solar intensity) or cooling (for weaker solar intensity). According to NASA research, reduced solar activity from the 1400s to the 1700s was likely a key factor in the “Little Ice Age” which resulted in a slight cooling of North America, Europe and probably other areas around the globe. (See additional discussion under The Last 2,000 Years.)

Håndværker - colic-help - skateboard - ekko - abstrakt

Changes in the Earth's orbit:

Changes in the shape of the Earth's orbit (or eccentricity) as well as the Earth's tilt and precession affect the amount of sunlight received on the Earth's surface. These orbital processes -- which function in cycles of 100,000 (eccentricity), 41,000 (tilt), and 19,000 to 23,000 (precession) years -- are thought to be the most significant drivers of ice ages according to the theory of Mulitin Milankovitch, a Serbian mathematician (1879-1958). The National Aeronautics and Space Administration's (NASA) Earth Observatory offers additional information about orbital variations and the Milankovitch Theory.

Håndværker - colic-help - skateboard - hitler - float

global climate in the past

Scientists have been able to piece together a picture of the Earth's climate dating back decades to millions of years ago by analyzing a number of surrogate, or "proxy" measures of climate such as ice cores, boreholes, tree rings, glacier lengths, pollen remains, and ocean sediments, and by studying changes in the Earth's orbit around the sun.

Håndværker - colic-help - skateboard - neandertal - owned

climate change

The Earth's climate has changed throughout history. From glacial periods (or "ice ages") where ice covered significant portions of the Earth to interglacial periods where ice retreated to the poles or melted entirely - the climate has continuously changed.

Håndværker - colic-help - skateboard - warming - population crash

Natural variability

Prior to the Industrial Era, the Medieval Climate Anomaly and Little Ice Age had defined the upper and lower boundaries of the climate's recent natural variability and are a reflection of changes in climate drivers (the sun's variability and volcanic activity) and the climate's internal variability (referring to random changes in the circulation of the atmosphere and oceans).

Håndværker - colic-help - skateboard - board - wallspeek - owned