Climate Change is Real

  

Human influence on climate clear.

 Human influence on the climate system is clear. This is evident in most regions of the globe, a new assessment by the Intergovernmental Panel on Climate
Change (IPCC) concludes.
It is extremely likely that human influence has been the dominant cause of the observed warming
since the mid-20th century. The evidence for this has grown, thanks to more and better
observations, an improved understanding of the climate system response and improved climate
models.
Warming in the climate system is unequivocal and since 1950 many changes have been
observed throughout the climate system that are unprecedented over decades to millennia. Each of the last three decades has been successively warmer at the Earth’s surface than any preceding
decade since 1850, reports the Summary for Policymakers of the IPCC Working Group I
assessment report, Climate Change 2013: the Physical Science Basis, approved on Friday by
member governments of the IPCC in Stockholm, Sweden.

“Observations of changes in the climate system are based on multiple lines of independent
evidence. Our assessment of the science finds that the atmosphere and ocean have warmed, the
amount of snow and ice has diminished, the global mean sea level has risen and the concentrations
of greenhouse gases have increased,” said Qin Dahe, Co-Chair of IPCC Working Group I.
Thomas Stocker, the other Co-Chair of Working Group I said: "Continued emissions of greenhouse
gases will cause further warming and changes in all components of the climate system. Limiting
climate change will require substantial and sustained reductions of greenhouse gas emissions."
“Global surface temperature change for the end of the 21st century is projected to be likely to
exceed 1.5°C relative to 1850 to 1900 in all but the lowest scenario considered, and likely to exceed 2°C for the two high scenarios,” said Co-Chair Thomas Stocker. “Heat waves are very likely to occur more frequently and last longer. As the Earth warms, we expect to see currently wet regions receiving more rainfall, and dry regions receiving less, although there will be exceptions,” he added.

Projections of climate change are based on a new set of four scenarios of future greenhouse gas
concentrations and aerosols, spanning a wide range of possible futures. The Working Group I report assessed global and regional-scale climate change for the early, mid-, and later 21st century. “As the ocean warms, and glaciers and ice sheets reduce, global mean sea level will continue to rise, but at a faster rate than we have experienced over the past 40 years,” said Co-Chair Qin Dahe.

The report finds with high confidence that 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.

Co-Chair Thomas Stocker concluded: “As a result of our past, present and expected future
emissions of CO2, we are committed to climate change, and effects will persist for many centuries
even if emissions of CO2 stop.”
Rajendra Pachauri, Chair of the IPCC, said: “This Working Group I Summary for Policymakers
provides important insights into the scientific basis of climate change. It provides a firm foundation
for considerations of the impacts of climate change on human and natural systems and ways to
meet the challenge of climate change.”