Climate change can be defined as a change in climatic variables, particularly temperature and precipitation, that occurs gradually over a long period of 50 to 100 years. It must also be understood that changes caused by human (anthropogenic) activity, particularly those related to fossil fuel consumption and land use.
Thus, changes caused by natural factors, such as additional aerosols from volcanic eruptions, are not considered climate change. For example, natural phenomena that lead to extreme weather conditions such as cyclones can occur within one year (interannual), and El-Nino and La Nina can occur within ten years (inter-decadal), cannot be classified as global climate change.
The human activities in question are those that have led to an increase in atmospheric concentrations, particularly in the form of carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O). These gases then determine the increase in temperature because they are like glass, transmitting shortwave radiation that is not hot but retains longwave radiation that is heated. As a result, the earth’s atmosphere warms up.
The impact of climate change :
The agricultural sector will be affected by the reduction in food productivity caused by the increased sterility of cereals, the decrease in the area that can be irrigated and the reduction in the efficiency of nutrient absorption and the spread of pests and diseases.
In some places in developed countries (high latitudes), the increase in CO2 concentration will increase productivity due to increased assimilation. Still, in the tropics than most developing countries, an increase in assimilation was not significant as respiration, which is also increased. Overall, if adaptation is not made, the world will experience a decline in up to 7% of food production.
However, with continued levels of adaptation, which means high costs, food production can be stabilized. In other words, stabilizing food production on climate change will be very expensive, for example, by improving irrigation facilities, adding inputs (seeds, fertilizers, insecticides/pesticides).
In Indonesia, CO2 concentrations will double compared to current rice production will increase to 2.3% if irrigation can be maintained. But if the irrigation system has not improved rice production, the CO2 concentration will fall to 4.4% (Matthews et al., 1995).
Warmer temperatures will lead to changes in plant species and ecosystems. Mountain areas will lose many of the original vegetation species and will be replaced by lowland vegetation species. The state of mountain water resources will also be susceptible to disturbance. The stability of land in mountainous areas is also disturbed, making it difficult to maintain the original vegetation. This impact is not as apparent in low latitude or low altitude areas. While forest fires are becoming more frequent in Indonesia, it has been challenging to link this incident to climate change as most (if not all) forest fires are caused by human activities related to land clearing.
This occurred in conjunction with the El-Nino events, as this phenomenon provides dry weather conditions that facilitate fires. However, as described above, El-Nino is a phenomenon of nature that has been associated with extreme climatic events in climate variability, not climate change in the sense described above. Population growth is putting pressure on water supply, particularly in urban areas.
Many urban residents have difficulty obtaining clean water, especially those with low incomes and low levels of education or skills. The impact of climate change, resulting in changes in temperature and precipitation, will affect water availability from surface runoff, groundwater, and other forms of reservoirs. By 2080, 2 to 3.5 billion people will experience water shortages.
Climate change is real and everyone needs to get sensitize about it and start to make amends for the future generations. It is a grave danger for small island nations that would disappear first when the glaciers would melt.