Atmospheric CO2 levels now at 400 ppm: A historic threshold crossed

Atmospheric CO2 levels now at 400 ppm: A historic threshold crossed

The world entered a new danger zone of climate change recently with levels of Earth-warming carbon dioxide (CO2) in the atmosphere crossing the threshold of 400 parts per million (ppm) . Such a level has never been experienced by humankind. Climate-change scientists fear that this may have catastrophic consequences in the years to come.

Why does CO2 level in the atmosphere matter?

Carbon dioxide (CO2) is the chief greenhouse gas that results from human activities and causes global warming and climate change. Global warming is mainly the result of CO2 levels rising in the Earth’s atmosphere. Both atmospheric CO2 and climate change are accelerating.

Climate scientists say humanity has years, not decades, to stabilize CO2 and other greenhouse gases (which include methane, nitric oxide, sulphur hexafluoride, perfluoro-carbons, hydrofluorocarbons, chloro-fluorocarbons etc.). Our failure to contain the emission of CO2 and other greenhouse gases will have disastrous consequences for weather patterns, human settlements, agro-ecosystems, ecosystems, biodiversity etc.

The concentrations of CO2 in the atmosphere are increasing at an accelerating rate from decade to decade.   The latest atmospheric CO2 data is consistent with a continuation of this long-standing trend.

The upper safety limit for atmospheric CO2 is 350 parts per million (ppm). Atmospheric CO2 levels have stayed higher than 350 ppm since early 1988.

Data collection for Atmospheric CO2

The world’s most current data for atmospheric CO2 is measured at the Mauna Loa Observatoy in Hawaii, USA.  Measurements are made and reported independently by two scientific institutions:  Scripps Institution of Oceanography and the National Oceanic and Atmospheric Administration (NOAA) of the USA.

The trends for atmospheric CO2 levels

The 2012 average annual concentration of CO2 in the atmosphere (Mauna Loa Observatory) is 393.84 parts per million (ppm).   The 2011 average was 391.65 ppm.

For the past decade (2003-2012) the average annual increase is 2.1 ppm per year.  The average for the prior decade (1993-2002) is 1.7 ppm per year.

Before the Industrial Revolution, CO2 levels were about 280 ppm.

The Intergovernmental Panel on Climate Change (IPCC), which informs policy makers, has said CO2 must be limited to 400 ppm for a temperature rise of 2-2.4 degree Celsius.

The U.N. is targeting a maximum temperature rise of two degrees Celsius on pre-industrial levels for manageable climate change.

A brief overview of global CO2 budget is given in the image below.


What are the likely impacts of global warming and climate change?

The effects of global warming are the ecological and social changes caused by the rise in global temperatures. There is a scientific consensus that climate change is occurring, and that human activities are the primary driver. Projections of future climate change suggest further global warming, sea level rise, and an increase in the frequency and severity of some extreme weather events.

Effects_of_global_warmingSome impacts from increasing temperatures are already happening.

  • Ice is melting worldwide, especially at the Earth’s poles. This includes mountain glaciers, ice sheets covering West Antarctica and Greenland, and Arctic sea ice.
  • Researcher Bill Fraser has tracked the decline of the Adélie penguins on Antarctica, where their numbers have fallen from 32,000 breeding pairs to 11,000 in 30 years.
  • Sea level rise became faster over the last century.
  • Some butterflies, foxes, and alpine plants have moved farther north or to higher, cooler areas.
  • Precipitation (rain and snowfall) has increased across the globe, on average.
  • Spruce bark beetles have boomed in Alaska thanks to 20 years of warm summers. The insects have chewed up 4 million acres of spruce trees.

Other effects could happen later this century, if warming continues.

  • Sea levels are expected to rise between 7 and 23 inches (18 and 59 centimeters) by the end of the century, and continued melting at the poles could add between 4 and 8 inches (10 to 20 centimeters).
  • Hurricanes and other storms are likely to become stronger.
  • Species that depend on one another may become out of sync. For example, plants could bloom earlier than their pollinating insects become active.
  • Floods and droughts will become more common. Rainfall in Ethiopia, where droughts are already common, could decline by 10 percent over the next 50 years.
  • Less fresh water will be available. If the Quelccaya ice cap in Peru continues to melt at its current rate, it will be gone by 2100, leaving thousands of people who rely on it for drinking water and electricity without a source of either.
  • Some diseases will spread, such as malaria carried by mosquitoes.
  • Ecosystems will change—some species will move farther north or become more successful; others won’t be able to move and could become extinct.

Climate change impacts on India

Indian Network for Climate Change Assessment (INCCA) released its first report in November 2010. It is the result of collective work of 45 scientists- on the impact of climate change in four regions of the country.

These regions are:

  1. The Himalayan region
  2. The North-East
  3. The Western Ghats
  4. The coastal areas

While the report admits that significant research gaps and lack of extensive databases are hampering Indian climate science, it attempts to assess the impact of climate change by 2030 in the above four areas in the sectors of agriculture, water, health and forests.
Some of the highlights of the report are as follows.

  • It projects a 1.7 to 2.2 degrees centigrade increase in annual temperatures, with the biggest increase coming in coastal regions.
  • Sea level and rainfall will also rise, with cyclones becoming more intense, though less frequent.
  • Flooding could increase up to 30 per cent.
  • Droughts may become more severe in the Himalayas.
  • Warmer weather will encourage mosquitoes, malaria could spread to new areas in the Himalayas, and see higher rates in the North East as well.
  • While irrigated rice may see marginal yield increases, maize, sorghum and apple could see reduced yields.
  • The increase in thermal humidity will lead to stress in livestock and a reduction in milk productivity.

International efforts to limit the levels of CO2 and other green house gases in the atmosphere

The Kyoto Protocol is an amendment to the United Nations Framework Convention on Climate Change (UNFCCC), an international treaty on global warming. The Kyoto Protocol is an international agreement setting targets for industrialised countries to cut their greenhouse gas emissions. The TARGETED GASES are:

  1. Carbon dioxide (CO2)
  2. Methane (CH4)
  3. Nitrous Oxide (N2O)
  4. Hydrofluorocarbons (HFCs)
  5. Perfluorocarbons (PFCs)
  6. Sulphur hexafluoride (SF6)

The Kyoto Protocol was adopted at the third session of the Conference of Parties (COP) to the UNFCCC in 1997 in Kyoto, Japan. It was based on principles set out in a framework convention signed in 1992.

On 16th February 2005 the 1997 Kyoto Protocol to control climate change finally became international law. The Kyoto Protocol was to expire in 2012 but during the UN Climate Summit 2011, held at Durban (South Africa), the nations agreed to extend the term of Kyoto Protocol’s operation beyond 2012 in the present form. The new expiration date of the Protocol is 2017 or 2020. Till then, a new agreement that replaces the Kyoto Protocol will be finalised.

At present, negotiators under the auspices of the U.N. are seeking by 2015 to develop a new, global climate treaty. Nations are simultaneously attempting to find short-term solutions pre-2020 to closing the growing gap between agreed carbon emission targets and the actual curbs required to contain warming.

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