Climate change will play havoc with our seasons and finely balanced agricultural sector unless serious efforts are made to reduce emissions.

An analysis of the potential impacts of global warming reveals the huge burden the economy will have to shoulder within just 40 years, with annual costs of up to €2bn possible for the agriculture sector alone due to drought, drops in crop yields and pests.

The warning comes as the United National Intergovernmental Panel on Climate Change (IPCC) revealed that immediate action was needed to reduce greenhouse gas emissions from transport, energy and the agricultural sectors to limit global warming to 2C by the end of the century.

Rising sea levels and risk of flooding, food shortages, drought and possible conflict would arise unless the amount of carbon being produced was halted and reductions implemented as soon as possible, its fifth assessment report on the state of the climate said.

The impacts of global warming were “severe, pervasive and irreversible”, it added. Dr Frank McGovern, from the Environmental Protection Agency (EPA), who represented Ireland during discussions to finalise the IPCC report, said the implications of failing to act would be catastrophic. “Unmitigated climate change is not something we like to consider,” he said.

“A scenario of unmitigated climate change, or business as usual greenhouse gas emissions, is likely to have significant consequences for Ireland. It would increase the risk of both direct and indirect climate change impacts. These would evolve over the course of this century and beyond. The details remain uncertain but some elements can be identified.