The UN warns that the concentration of carbon dioxide exceeded for the first time a historic threshold that marks a disturbing trend toward global warming planet. The increase of CO2 impact on an increase of 2.4 ° C, over the target set by the international community to prevent the proliferation of extreme events.
“With 400 ppm (parts per million) of CO2 in the atmosphere have surpassed the historical limits and have entered a danger zone,” said the UN chief climate, Christiana Figueres in a dated statement in Bonn ( Germany).
Indeed, on the observatory in Mauna Loa volcano in Hawaii recorded a CO2 concentration of 400.03 ppm, the US Oceanic and Atmospheric Agency (NOAA) reported.
The move was timely, but experts estimate that the annual average for 2013 certainly exceeded 400 ppm, a symbolic figure that marks a disturbing trend toward warming the planet.
With an annual average of 400 ppm CO2 concentration, the expected global warming will be at least 2.4 ° C, predicted in its latest report the UN experts on Climate Change (IPCC). The outlook is pessimistic: CO2 emissions in the atmosphere continue to rise and if the trend continues the temperature could rise between 3 and 5 ° C.
“The world must wake up and take note of what this means for the safety of human beings, for their welfare and economic development,” warned Figueres.
In 2009, the international community a maximum target of + 2 ° C compared to levels before the industrial age was set. Scientists estimate that from that ceiling, the earth will be changed its climate system marked by extremes.
“There is still a chance to avoid the worst effects of climate change,” said Figueres, while urging those responsible for the planet a “political response capable of facing this challenge.”
The amount of greenhouse gases in the atmosphere reached a new record high in 2013, due to accelerated rise in levels of carbon dioxide, as indicated in the Annual Bulletin of the World Meteorological Organization (WMO) on GHG. This makes the need for concerted international action against the acceleration of climate change, the consequences could be devastating, it is more pressing than ever.
Bulletin reveals, between 1990 and 2013 the radiative forcing, which causes a heating effect of climate- experienced a 34% increase due to greenhouse gas long term, such as carbon dioxide (CO2) methane (CH4) and nitrous oxide (N2O).
In 2013 the concentration of CO2 in the atmosphere reached 142% of the level of preindustrial era (before 1750), the 253% methane and nitrous oxide 121%.
The observations of the network of Global Atmosphere Watch (GAW) of WMO showed that CO2 levels had increased more between 2012 and 2013 than during any year since 1984. Preliminary data suggest that this increase may obey the reducing the amount of CO2 absorbed by the biosphere of the Earth, added to the constant increase in emissions of that gas.
In the WMO Bulletin on greenhouse gases it is reported, and not atmospheric concentrations of these gases emissions-. Emission means the amount of gas to the atmosphere and the amount remaining concentration in the atmosphere after the complex interactions that take place between the atmosphere, biosphere and oceans. About a quarter of total CO2 emissions are absorbed by the oceans and another quarter by the biosphere, thereby reducing the amount of this gas in the atmosphere.
The increase of CO2 in the atmosphere is damped by the absorption of the gas by the oceans, but they pay heavily for it. There seems no precedents for the current rate of acidification of the oceans, at least in the last 300 million years, according to an analysis contained in the report.
“We have the absolute certainty that the climate is changing and that weather conditions are becoming ever more extreme due to human activities such as burning fossil fuels,” said WMO Secretary-General Michel Jarraud.
“The Bulletin of greenhouse gases shows that, far from diminishing, the concentration of carbon dioxide in the atmosphere increased last year at a rate that had not been in nearly 30 years. We must reverse this trend by reducing emissions of CO2 and other greenhouse gases as a generalized measure, “he said. “We are running out of time.”
“Carbon dioxide remains in the atmosphere for hundreds of years in the ocean and much more. CO2 emissions of the past, present and future have a cumulative effect on both the warming and acidification of the oceans. The laws of physics are not negotiable, “said Mr. Jarraud.
“The Bulletin on greenhouse gases is a scientific basis for decision-making. We have the knowledge and tools to try to make the temperature rise is limited to 2 ° C maximum and thus give a chance to our planet and the future of our children and grandchildren. You can not claim ignorance as an excuse for inaction, “said Mr. Jarraud.
“The inclusion of a section on ocean acidification in this issue of WMO Bulletin on greenhouse gases was necessary and appropriate. It is time that the ocean, as one of the main determinants of the planet’s climate and mitigating climate change becomes central to the debate on climate change, “said Wendy Watson-Wright, Executive Secretary the Intergovernmental Oceanographic Commission of the United Nations Educational, Scientific and Cultural Organization (UNESCO).
“If global warming is not considered a sufficient reason to reduce CO2 emissions, acidification of the oceans should be because its effects are already being felt and will only increase over the decades. I echo the concern expressed by Mr. Jarraud, WMO Secretary-General: We are being depleted over time. ”
Carbon dioxide contributed about 80% to 34% increase experienced by the radiative forcing of the atmosphere due to greenhouse gas long term between 1990 and 2013, the annual rate of greenhouse gases Administration National Oceanic and Atmospheric Administration (NOAA) of the United States.
The amount of CO2 in the atmosphere worldwide reached 396.0 parts per million (ppm) in 2013. The increase of this gas in the atmosphere of 2012-2013 was 2.9 ppm, which is the highest annual increase for the period from 1984 to 2013. The CO2 concentrations are subject to seasonal and regional fluctuations. If growth continues at the current pace, it is expected that the global annual average concentration of CO2 exceeds the symbolic threshold of 400 ppm in 2015 or 2016.
Methane gas is the second most important greenhouse durability. Approximately 40% of methane emissions to the atmosphere from natural sources (wetlands, termites, etc.), while about 60% come from human activities (livestock, rice cultivation, fossil fuel exploitation, landfills, combustion biomass, etc.). Atmospheric methane reached a new peak in 2013, around 1824 parts per billion, due to increased emissions from anthropogenic sources. After a period of stabilization, atmospheric methane has been increasing again since 2007.
Nitrous oxide emissions to the atmosphere are both natural sources (almost 60%) and anthropogenic (approximately 40%), especially since they come from the oceans, soil, biomass burning, fertilizer use, and various industrial processes. In 2013 the atmospheric concentration was about 325.9 parts per thousand millones.Su effect on the climate over a period of 100 years is 298 times higher than the same emissions of carbon dioxide. This gas also contributes significantly to the destruction of the stratospheric ozone layer, which protects us from the harmful ultraviolet rays of the sun.
For the first time, the Bulletin contains a section on ocean acidification, prepared in collaboration with the International Project on Ocean Carbon Coordination (IOCCP) of the Intergovernmental Oceanographic Commission (IOC of UNESCO), the Scientific Committee on Oceanic Research (SCOR) and the International Centre for Coordination on Ocean Acidification of the International Atomic Energy Agency (IAEA).
The ocean currently absorbs one quarter of anthropogenic CO2 emissions, thereby limiting the increase in atmospheric CO2 from burning fossil fuels. Absorbing larger quantities of this gas alters ocean marine carbonates system and causes an increase in the acidity of water. Increased acidity and that can be measured, because the oceans absorb approximately 4 kg of CO2 per person per day.
As is clear from indirect data from paleoclimate records, there seems no precedents for the current rate of acidification of the oceans, at least in recent years 300millones. Acidification will continue to accelerate in the future, at least until mid-century, according to the projections of the Earth system models.
The possible consequences of ocean acidification on marine organisms are complex. Especially worrying is the response to acidification of calcifying organisms such as corals, algae, molluscs and other species of plankton, since their ability to build shells, shells or material for their skeletons (through calcification) depends on the ion concentration carbonate. For many organizations, calcification decreases with increasing acidification. Among other consequences that acidification has to organisms include its lower rate of survival, development and growth as well as changes in their physiological functions and decreased biodiversity.