Here’s a summary statement from a Worldwatch Institute report helpfully titled, “Agriculture and Livestock Remain Major Sources of Greenhouse Gas Emissions:”
“Global greenhouse gas (GHG) emissions from the agricultural sector totaled 4.69 billion tons of carbon dioxide (CO₂) equivalent in 2010, an increase of 13% over 1990 emissions.”
Those totals seem ominous; 4.69 billion tons is a huge number, and a 13% increase is certainly worrisome.
But let’s put those figures in perspective, shall we? Since the Worldwatch folks certainly won’t bother doing so, it’s important to analyze and compare both the data themselves and the rate of increase within the larger picture of overall GHG emissions.
The data source I used is the same one Worldwatch used: the UN Food and Agricultural Organization’s FAOSTAT online GHG emissions calculator.
For starters, the 13% increase in agricultural GHGH emissions represents a comparison that spans more than 20 years. During that time period, the overall annual increase in yield for such key crops as corn (1.77%), wheat (0.52%, rice (0.92%) and soybeans (1.08%) also increased, as well. Extending those annual increases across the same time period, while overall agricultural GHG emissions rose 13%, global yields on corn increased 40%; wheat 11%; rice 22%; and soybeans 24%.
(By the way, overall agricultural productivity over the last 50 years is approaching an 80% increase, according to FAO, dwarfing the increase in GHG emissions during that same time period).
Thus, at the same time that anti-livestock groups are wringing their hands over agriculture’s contribution to global warming, productivity increases for key food crops greatly exceeded the amount of GHG emissions resulting from overall global farming activities.
In other words, although GHG emissions went up, the net contribution of agriculture per bushel of food produced decreased significantly.
That’s cause for celebration, not consternation.
The real source of the problem
Then there are the raw numbers themselves.
By comparison with the estimated 4.69 billion tons of GHG emissions attributed to agriculture, global CO₂ emissions from worldwide transportation activities totaled 6.76 billion tons in 2010, according to UN data. That’s a 44.4% greater source of emissions, even granting FAO its questionable calculations regarding the total GHG contributions of global agriculture.
Even more dramatic, total GHG emissions from power generation using fossil fuels in 2010 exceeded 12.4 billion tons, nearly triple the amount attributed to agriculture.