And, this will not be the first time the Intergovernmental Panel on Climate Change (IPCC) has erred on the side of caution. The last major UN climate assessment, AR4 in 2007, projected a controversial low-ball sea level rise. However, AR4 did project runaway temperature rises of 6 degreesC or more by the end of the century.
That level of increase is now thought unlikely by AR5 scientists. They project that average land and sea temperatures may possibly increase 4 degreesC above present levels -- enough to devastate crops and make life in many cities unbearably hot.
A main focus of AR5 is convincing policymakers to take actions that will limit global surface temperature increase to around 2 degreesC. The IPCC scientists found that to hold warming to 2 degreesC, total emissions cannot exceed 1,000 gigatonne (2,204 trillion lb) of carbon. Yet by 2011, more than half of that total allowance, 531 gigatonne (1,170 trillion lb), had already been emitted. And, global industrial emissions since 1751 is around 365 billion metric tonnes and may be as high as 1,450 gigatonne (3,196 trillion lb) of carbon.
The AR5 authors themselves claim that with business-as-usual emissions, their global 2 degreesC warming threshold will be breached within 30 years, by 2043. Furthermore, the slow progress of global climate talks makes the IPCC's 'carbon budget', and so-called safe limit of a 2 degreesC rise, impossible to keep.
After a slight dip in GHG emissions caused by the 2008-9 economic recession, emissions are rising again. Moreover, the impacts associated with 2 degreesC have been revised upwards so that 2 degreesC now represents the threshold of extremely dangerous climate change.
In choosing the conservative approach of trying to stay under 2 degreesC, the IPCC report fails to explore the catastrophic impacts and vulnerability in the business as usual case where the Earth warms up 4 degreesC to 5 degreesC (7 degreesF to 9 degreesF). And, AR5 has less to say about even higher warming, which the latest science suggests we are headed toward.
One of the leading causes of global warming is livestock production and Westerners' animal-heavy diets, which impacts the poor, water, forests, soil, oceans, biodiversity and health. Livestock production releases vast amounts of carbon dioxide, and much more powerful greenhouse gases - methane and nitrous oxide. And, demand for meat is projected to increase by 50 percent from 2013 to 2025.
Even if the world went fossil free by 2100, increasing animal consumption will continue to cause catastrophic climate change. Demand for animal products is projected to increase by 50 percent from 2013 to 2025. To stop rapid global warming and preserve a future for children, we must reduce the burning of fossil fuels, as well as greenhouse gas emissions released from the production and consumption of animal products.
Excerpt from the book, "Meat Climate Change," see http://meatclimatechange.org/