The statements and facts presented are derived from the IPCC Working Group summary for policymakers, (Working Group I summary for policymakers, the Physical Science Basis).
Excerpts from Video
Our planet is vast. It is difficult to comprehend the scale. It is difficult too to comprehend the scale of humanity and the vast changes we’ve wrought in a lifetime.
Population, production and consumption have grown exponentially. Roads, railways, airlines, shipping routes. The digital revolution. We’ve created a globally interconnected society. Evidence is mounting we’ve entered the Anthropocene.
The Intergovernmental Panel on Climate Change assesses the risks and options for societies. Its latest report states it is extremely likely humans are the dominant cause of warming in the past 60 years.
Humanity is altering Earth’s life support system. Carbon dioxide emissions are accelerating. Greenhouse gas levels are unprecedented in human history. The climate system is changing rapidly.
Without deep emissions cuts, it is likely Earth will cross the target of two degree Celsius above pre-industrial levels. The target set by international policy. This could happen as early as 2050. If emissions keep rising at current rates, a four-degree rise by 2100 is as likely as not. This marks a vast transformation of our planet.
Video: Climate change the state of the science (data visualization)
Published on Nov 19, 2013
Produced by the International Geosphere-Biosphere Programme and Globaia
Standard YouTube License
What is our Carbon Budget?
The global carbon budget is the balance of the exchanges (incomes and losses) of carbon between the carbon reservoirs or between one specific loop (e.g., atmosphere ↔ biosphere) of the carbon cycle. An examination of the carbon budget of a pool or reservoir can provide information about whether the pool or reservoir is functioning as a source or sink for carbon dioxide (Wikipedia).
The Global Carbon Project report the following in its 2013 Carbon Project report:
Carbon dioxide (CO2) emissions from fossil fuel burning and cement production increased by 2.1% in 2012, with a total of 9.7±0.5 GtC (billion tonnes of carbon) emitted to the atmosphere, 58% above 1990 emissions (the Kyoto Protocol reference year). Emissions are projected to increase by a further 2.1% in 2013. In 2012, the ocean and land carbon sinks respectively removed 28% and 23% of total (fossil fuel and land use change) CO2. The land sink in 2012 was much less than in 2011, a year of a strong La Niña weather pattern.
“Can we remain below two degrees,” asks the IPCC. “It is possible. But it is up to societies now to decide the future we want. For a likely chance of achieving the two-degree target, societies can emit another 250 billion tonnes of carbon.”
We burn about 10 billion tonnes of carbon a year. At current rates we will use this budget in about 25 years.
Some IPPC Observations (from IPCC Working Group Summary for Policymakers)
Changes in the Climate System: Warming of the climate system is unequivocal, and since the 1950s, many of the observed changes are unprecedented over decades to millennia. The atmosphere and ocean have warmed, the amounts of snow and ice have diminished, sea level has risen, and the concentrations of greenhouse gases have increased.
Atmosphere: Each of the last three decades has been successively warmer at the Earth’s surface than any preceding decade since 1850. In the Northern Hemisphere, 1983–2012 was likely the warmest 30-year period of the last 1400 years.
Oceans: Ocean warming dominates the increase in energy stored in the climate system, accounting for more than 90% of the energy accumulated between 1971 and 2010. It is virtually certain that the upper ocean (0−700 m) warmed from 1971 to 2010, and it likely warmed between the 1870s and 1971.
Cryosphere: Over the last two decades, the Greenland and Antarctic ice sheets have been losing mass, glaciers have continued to shrink almost worldwide, and Arctic sea ice and Northern Hemisphere spring snow cover have continued to decrease in extent.
Sea Level: The rate of sea level rise since the mid-19th century has been larger than the mean rate during the previous two millennia. Over the period 1901 to 2010, global mean sea level rose by 0.19 m.
Carbon and Other Biogeochimical Cycles: The atmospheric concentrations of carbon dioxide, methane, and nitrous oxide have increased to levels unprecedented in at least the last 800,000 years. Carbon dioxide concentrations have increased by 40% since pre-industrial times, primarily from fossil fuel emissions and secondarily from net land use change emissions. The ocean has absorbed about 30% of the emitted anthropogenic carbon dioxide, causing ocean acidification.
Humanity’s carbon footprint is huge. Societies will need to adapt to climate change. The scale of change depends on decisions made now.