Certainly, climate change will affect GNP of countries that depend much on agriculture. This means that developing countries and under-developed countries are hard hit. Climate change will cause GNP to shrink, and make our countries poorer. It directly affects, reduces, food security. See this paper. Thanks.
climate change is a long-term problem, there is a growing body of opinion that the effects are already being felt. we find larger effects in poor than rich countries, growth effects rather than level effects and impacts of temperature on economic and political activity are important patterns that models of climate’s economic impacts should be able to reproduce.
It will adversely affect the GDP as climate change will deplete the natural resources or reduce their productivity. At the same time, the population of harmful organisms will be significantly increased, which will reduce the efficiency of human resources and livestocks. Increased expenditure on health will affect the savings of individuals, which will affect the macroeconomy. Further, as it often takes a heavy toll of resources including infrastructure, the economy will struggle to bounce back. Climate change affects people across sectors and terrain. The rural and indigenous people are always the worst sufferers.
Climate change - fluctuations in the Earth's climate as a whole or its individual regions over time, lead to statistically significant deviations from the forecast parameters of long-term values over a period of decades to millions of years. Taking into account changes in both the average values of weather parameters and changes in the frequency of extreme weather events.
It is well known that the climate has a significant impact on many sectors of the economy. Under the influence of climatic conditions of the gross national product may vary by a few percent.
Climate change if they can affect the gross domestic product (GDP) of a country, but the relationship is not direct or short-term, since other factors: political, economic and production models, for this to happen, because usually GDP is relatively stable in the short term as long as there is no sudden change in the economic model.
Taking for example my country Mexico, there are changes in the environment by climate change, torrential rains and hurricanes destroy populations lose all or part of its infrastructure and this leads to rebuild large economic costs not covered, impoverishing the population or increasing debts to local government (municipal), state or country.
On the other hand, the destruction of forests by illegal logging, pollution of water sources by mining, pollution of drinking water by sewage, etc ... All this contributes to alter the ecological environment in some regions of the country , causing increased climate alteration, added to the existing and accentuating the precarious state.
Finally the country's government tries to keep the economy stable (Macroeconomics) with external debt, but inside there are large groups of impoverished people and only a minority (oligarchy) enriched. This is an additional factor to break the ecological balance, as the impoverished people try to survive on exploiting its environmental wealth and the ruling class or economic power with influence peddling and corruption contribute to the installation of dirty industries that predate more environmentally environment and disturb the ecological balance.
As you can see, the relationship between GDP and Climate Change is not direct, it is in interaction with the factors described above.
What if directly alters GDP is political change and economic model of the country.
The team's best estimate is that climate change will reduce global economic production by 23 percent in 2100. “Historically, people have considered a 20 percent decline in global Gross Domestic Product to be a black swan: a low-probability catastrophe,” Hsiang warned.