Carbon dioxide levels do show natural variability, but only since the industrial revolution have values moved beyond the “natural bound” of 270 to 280 ppm. Current levels are approximately 390 ppm.
Global livestock production 1) appropriates around 3% of global net primary productivity, 2) leads to collateral carbon flows such as losses to the atmosphere by tropical deforestation for pasture and croplands, and 3) is a significant source of carbon dioxide emissions.
Globally, livestock is the largest methane source emitter (third in the United States). Atmospheric methane is increasing, can linger in the atmosphere for ∼9 to 15 years, and is more than 20 times more effective at trapping heat than carbon dioxide.
Carbon losses associated with grazing systems could be reduced through proactive management to conserve vegetation cover/soil carbon storage and integration of climate fluctuations in livestock production systems.
Human-related activities are a clear contributor to climate change, and changes are happening on time scales much shorter than natural climate changes.
Humans may not perceive that average temperatures are warmer in 2100, but they will notice when coastal cities are facing sea level rise, days exceeding 100 degrees Fahrenheit increase, food prices fluctuate because of changing crop yields or livestock productivity, or diseases appear in new latitudes because of a more favorable climate.
The apparent controversy over climate change is rooted in a campaign by special interests to create reasonable doubt (e.g., tobacco industry and smoking) or basic lack of understanding of simple climate, science, and statistical principles.
Climate change will also affect livestock production and practices.
Sustainable pathways exist to reduce atmospheric carbon loading.