Our planet is constantly changing. Natural cycles balance and regulate Earth and its atmosphere. Human activities can cause changes to these natural cycles. Life on Earth is well adapted to our planet’s cycles. In our solar system, Earth is the only planet with air to breathe, liquid water to drink, and temperatures that are just right for life as we know it. Because our existence depends on our planet and its climate, we need to understand how what we do affect the Earth.
Climate is the average course or condition of the weather at a place usually over a period of years as shown by temperature, wind velocity, and precipitation a healthful climate a warm, humid climate. Whereas Climate change is the variation in global or regional climates over time. It reflects changes in the variability or average state of the atmosphere over time scales varying from decades to millions of years. These changes can be caused by processes internal to the Earth, external forces (e.g. variations in sunlight intensity) or, more recently, human activities.
In recent usage, especially in the context of environmental policy, the term “climate change” often refers only to changes in modern climate, including the rise in average surface temperature known as global warming. In some cases, the term is also used with a presumption of human causation, as in the United Nations Framework Convention on Climate Change (UNFCCC). The UNFCCC uses “climate variability” for non-human caused variations.
Earth has undergone periodic climate shifts in the past, including four major ice ages. These consisting of glacial periods where conditions are colder than normal, separated by interglacial periods. The accumulation of snow and ice during a glacial period increases the surface albedo, reflecting more of the Sun’s energy into space and maintaining a lower atmospheric temperature. Increases in greenhouse gases, such as by volcanic activity, can increase the global temperature and produce an interglacial period. Suggested causes of ice age periods include the positions of the continents, variations in the Earth’s orbit, changes in the solar output, and volcanism.[55]
Agriculture contributes substantially to global climate change. The sector accounts for a fifth of greenhouse gas (GHG) emissions when one considers the full life cycle of production including agriculture’s role in deforestation. This sector contributes 14 % to global GHG emission
~1/3 due to methane (livestock)
22x more potent than CO2 This
1/3 due to nitrous oxide (N fertilizers)
300x more potent than CO2
And drives Land Use Change ~15 % global emissions
This a massive number, comparable in scale to the transportation sector. Further, this ratio can be even higher in developing countries where agriculture and forestry sectors together often account for a majority of total emissions. Yet, historically, climate negotiators and policy makers have paid relatively little attention to the agricultural sector in the global effort to curb climate change.
In recent years, there have been a number of developments which indicate a positive shift towards incorporating climate into a broader agricultural agenda.
Yet, still more resources have to be brought to bear on the intersection of agriculture and climate change, particularly as there are multiple, complex challenges in addressing this nexus. Production is exceedingly diffuse, the demand for carbon intensive meat is increasing, there are research needs and challenges to mitigate agricultural emissions, and there are very high levels of uncertainty associated with the mitigation potential of various interventions. While it will be a persistent challenge, we have the resources needed to create agricultural systems that are more productive and less GHG intensive.