New evidence shows that the Arctic climate may be more sensitive to the greenhouse effect than previously believed and that current levels of atmospheric carbon dioxide may already be high enough to result in significant and irreversible changes in Arctic ecosystems.

A new international study, led from the University of Colorado at Boulder, said that while the annual average temperature of Ellesmere Island, located in the Arctic, was made between 2.6 and 5.3 million years (during the Pliocene ) far higher than today, CO₂ levels were only slightly higher than at present. The vast majority of climatologists agree that the Earth is warming due to increasing atmospheric concentrations of greenhouse gases, generated mainly by human activities that require burning fossil fuels and clearing forests. (more…)

In an analysis of the last 1.2 million years, Lorraine Lisiecki, geologist at the University of California at Santa Barbara has discovered a pattern that connects the regular changes of Earth’s orbital cycle to changes in Earth’s climate.

Lisiecki conducted climate analysis by examining ocean sediment cores. These cores were collected in 57 different places of the world. Analyzing sediment, scientists can reconstruct the climate of the past million years. Lisiecki’s contribution is the climate record connection with the planet’s orbital cycle.

It is known that the Earth’s orbit around the Sun changes the shape at every 100,000 years. The orbit becomes more circular or more elliptical, i.e., its eccentricity varies. A related issue is the 41,000-year cycle that describes the tilt of Earth’s axis. (more…)

Plausible scenarios of global warming in the worst case may involve temperatures lethal to humans in the next century, according to results of an investigation conducted by experts from Purdue University in the United States and the University of New South Wales South, Australia.

For the first time, we calculated wet bulb temperature (WB temperature) higher tolerable and disturbing conclusion is that this threshold could be exceeded for the first time in human history where the emissions of greenhouse gases continue without being mitigated. (more…)

The seasonal monsoon rains in Asia feed almost half the world’s population, and when these rains do not arrive, many people may go hungry, sometimes to disastrous ends. New research, based on the analysis of growth rings of trees, has provided more detailed record to date of at least four terrible drought, which shook the Asian continent during the last thousand years, from one that China could have influenced the fall of the powerful Ming Dynasty in 1644, to one that caused tens of millions from starvation in the late 1870s. (more…)

To have a clear idea of what can happen when the carbon cycle is altered on Earth, which is both cause and consequence of climate change, scientists can study a phenomenon occurred for about 720 million years.

The new data provided by a team of geologists directed from Princeton University suggest that a superglaciacion known as “Snowball Earth”, which may have covered the continents and oceans with a thick layer of ice, a drastic change in the carbon cycle. This change could, in turn, have led to ice ages that followed. (more…)

A new study concludes that the future effects of global warming could be significantly altered in small areas action specific local movements of air masses in mountainous or complex topography, perhaps doubling or even tripling, increasing temperature in some cases.

The authors of the study, from Oregon State University, used historical data, unique of its kind, obtained from the HJ Andrews Experimental forest located in the state of Oregon, to study potential changes in temperature caused by hills slopes and valleys adjacent to them. (more…)

13,000 years ago, Earth was hit by thousands of cometary fragments for an hour, causing a catastrophe of the kind suffered by the area of Tunguska in 1908, but to a much larger scale, which included a notable cooling of the planet. This is the conclusion they reached in a new study.

The cooling of 8 degrees Celsius interrupted the warming that was taking place at the end of the last ice age and caused it to resume the advance of glaciers.

Several lines of evidence have been found that this abrupt climate change was associated with any extraterrestrial event extraordinary. The border between the before and after the event is marked between the geological layers as a black layer a few inches thick, present in many places throughout the United States. (more…)

The decade 2000-2009 was the warmest since modern measurements began, and 2009 achieved a draw as the second warmest year in this disturbing list, as shown by a new analysis of global surface temperatures. Re-analysis, conducted annually by the NASA Goddard Institute for Space Studies (GISS), also shows that for the Southern Hemisphere in 2009 was the warmest year in recorded history.

2008 was the coldest year of the decade, due to the strong cooling of the tropical Pacific Ocean, but in 2009 global temperatures returned to near record numbers. Temperatures last year were only surpassed by 2005 the warmest year of the international meteorological record, and matched to those of other years 1998, 2002, 2003, 2006 and 2007 in the second on the list.

Over the past three decades, temperature records show an upward trend of about 0.2 degrees Celsius per decade, according to the study of GISS. The largest increases in the decade 2000-2009 were observed in the Arctic and parts of Antarctica. (more…)

A fossil shells of land snail found in ancient soils of the Canary Islands show that the Spanish archipelago off the northwest coast of Africa has become increasingly dry during the past 50,000 years.
Land snail shells are abundant, and sensitive to environmental changes, such as fossils, are well preserved. Measurements of changes in the ratios of oxygen isotopes in fossil shells can provide information on changes in ancient climate.

The isotopic analysis performed on fossil shells of land snail from the Canary Islands show oxygen isotope ratios suggest that the relative humidity was higher in the islands 50,000 years ago. This is the interpretation of the results have made the study’s authors, Yurena Yanes and Crayton J. Yapp, both the Department of Earth Sciences at Southern Methodist University in Dallas, Texas. (more…)