viernes, 27 de enero de 2012
The first 11 years of the 21st century experienced notably higher temperatures compared to the middle and late 20th century. The only year from the 20th century in the top 10 warmest years on record is 1998.
Higher temperatures today are largely sustained by increased atmospheric concentrations of greenhouse gases, especially carbon dioxide. These gases absorb infrared radiation emitted by Earth and release that energy into the atmosphere rather than allowing it to escape to space. As their atmospheric concentration has increased, the amount of energy "trapped" by these gases has led to higher temperatures.
The carbon dioxide level in the atmosphere was about 285 parts per million in 1880, when the GISS global temperature record begins. By 1960, the average concentration had risen to about 315 parts per million. Today it exceeds 390 parts per million and continues to rise at an accelerating pace.
Further information and an animation map about global temperatures since 1880 at:
jueves, 5 de enero de 2012
An inevitable decline of oil production: One more reason so as to develop renewable energies and efficient use of energy
Olivier Rech, responsible for petroleum issues at the International Energy Agency from 2006 to 2009, expects an inevitable overall decline of oil production "somewhere between 2015 and 2020".
He says: Outside OPEC, (which represents 58% of production and 23% of global reserves) things are clear: of 40 million barrels per day (mb/d) of conventional petroleum extracted from existing fields, we face an annual decline on the order of 1 to 2 mb/d. For OPEC production (42% of production and 77% of global reserves) he says that the data are still opaque and he notes that Barclays and Goldman Sachs banks estimate that the spare production capacity of OPEC, more particularly that of Saudi Arabia, is significantly lower that what is officially claimed.
Total evokes the possibility of maintaining production on a plateau of about 95 mb/d until 2030.
He says that is true. The production of oil has already been on a plateau since 2005 at around 82 mb/d[NB: with biofuels and coal-to-liquid, we approximate 88 mb/d for all liquid fuels.] It appears to him impossible to go much higher. Since demand is still on an increasing trajectory (unless, possibly, the economic crisis engulfs the emerging economies), He expects to see the first tensions arising between 2013 and 2015.