Clouds over the Atlantic Ocean on the east coast of the United States.While the U.S. Government remains in shutdown mode, the U.K. Department of Energy and Climate Change (DECC) has published its summary of the key points and questions about the UN IPCC’s 5th Assessment Report. According to this document, “climate change is happening now and greenhouse gas emissions from human activities are the dominant cause.”
The document states that climate change will continue over the decades and centuries to come in the absence of significant emission reductions. Among the evidence to that claim the document lists the following:
- Temperatures have risen by about 0.8°C over the last century.
- Each of the last three decades has been successively warmer than the previous decade and the last 30 years was likely the warmest period in 1400 years in the Northern Hemisphere.
- The frequency of heat-waves and intense rainfall events in many regions has increased.
- The oceans are absorbing carbon dioxide and are becoming more acidic.
- Global sea levels have risen by 20 cm since the beginning of the last century and the rise is accelerating.
- Glaciers are receding around the world and permafrost is thawing.
- Seasonal snow cover in the Northern Hemisphere is declining.
- Arctic sea ice cover in the summer has reduced on average by about 40% since 1979 and is happening much faster than anticipated.
The U.K. DECC also points out that, according to the new IPCC climate report, humans are responsible for the global warming with 95% confidence. Specifically, “it is extremely likely that human activity is the dominant influence on climate change over the last 50 years and is responsible for more than half of the observed global temperature rise.”
According to the IPCC climate report summary, as greenhouse gas emissions continue, the warming of the globe will continue and without serious efforts to reduce greenhouse gas emissions, global temperatures are likely to rise by more than 2°C over the next century and could rise by as much as 5°C. The global sea level is predicted to rise between 0.26 and 0.81 m by the end of this century and it will continue to rise for centuries to come.
The IPCC report also states that, despite the recent pause in global warming, “there is plenty of other evidence for continuing climate change.” The report notes that “the climate system is complex and periods of slow-down and speed-up in global temperature trends have occurred before and are expected to occur again” and states that “warming of the planet is dominated by the heat entering the oceans, accounting for over 90% of the total warming and there is evidence the oceans continued to warm during this period.”
Full text of the report is available on the IPCC website.
