Governments, business leaders and development banks have two years to take action to prevent much more severe climate change. This was announced by UN climate chief Simon Steele, quoted by "Reuters".
He warned that global warming is slipping off the politicians' agenda.
Scientists say halving climate-damaging greenhouse gas emissions by 2030 is crucial to stopping temperatures rising by more than 1.5°C, which would lead to more extreme weather and heat.
However, last year the world's CO2 emissions increased to a record high. Current commitments to combat climate change are unlikely to reduce global emissions by 2030.
Steele stressed that the next two years are "essential to saving our planet".
"We still have a chance to reduce greenhouse gas emissions with a new generation of national climate plans. But we need these stronger plans now," he insisted.
Steele said the leading G20 economies - together responsible for 80% of global emissions - urgently needed to step up.
The main task for this year's UN climate talks is for countries to agree a new climate finance target to support developing countries trying to transition from fossil fuels and combat climate change.< /p>
Steele said more climate finance needed to be secured through debt relief, cheaper finance for poorer countries, new sources of international finance such as a tax on shipping emissions and reforms to the World Bank and the International currency fund, which are holding their annual spring meetings this month.
In addition to more funding for the World Bank's International Development Association, Steele also pushed for a review of capital requirements and expanded use of climate-resilient debt clauses, which suspend debt payments in the event of natural disasters.
In a year with a number of elections around the world - from India to South Africa and the United States - Steele warned that too often climate action is "slipping off the agenda of governments".
A range of politicians, from Republican Donald Trump in the United States to far-right parties seeking victory in the upcoming EU elections, have rejected climate policies while courting voters.