The IPCC climate change report makes it clear that the world will witness greater sea level rise, higher frequency of droughts and floods, and heatwaves and countries like India with large populations dependent on the agricultural and fishery sectors, would be highly impacted, an environmental think-tank on Monday said.The IPCC report makes it clear that the impact of 1.5 degrees Celsius warming is greater than what was anticipated earlier while the impacts at 2°C are "catastrophic" for the poor and for developing nations like India, the Centre for Science and Environment (CSE) said.Avoiding global climate chaos will require a major transformation of society and the world economy that is "unprecedented in scale," the UN said Monday in a landmark report that warns time is running out to avert disaster.At current levels of greenhouse gas emissions, we could pass the 1.5 C marker as early as 2030, and no later than mid-century, the UN's Intergovernmental Panel for Climate Change (IPCC) reported with "high confidence".The US is the "biggest" obstacle to forming a global coalition to fight climate change and the world needs to unite against the "obstructive approach" of the US, the CSE said while asserting that Paris Agreement and the United Nations Framework Convention on Climate Change (UNFCCC) cannot be the only way ahead to address the climate change."The world needs a 'Plan B' to address climate change. India must take the lead in forming a global coalition for a 1.5°C world to save its poor and vulnerable population," CSE said."Even at a little over 1.0°C warming, India is being battered by the worst climate extremes – it is clear that the situation at 1.5°C is going to worsen. The new report from IPCC has served us a final warning that we must get our act together -- now and quickly," said Sunita Narain, Director General, CSE.CSE Deputy Director General Chandra Bhushan said the report makes it clear that the impact of 1.5°C warming is greater than what was anticipated earlier."Accordingly, the world would witness greater sea level rise, increased precipitation and higher frequency of droughts and floods, hotter days and heatwaves, more intense tropical cyclones, and increased ocean acidification and salinity."Countries like India, with large populations dependent on the agricultural and fishery sectors, would be highly impacted," he said.The report points out that the risk transition from 1.5°C to 2°C is very high and that the effects at 2°C will be more devastating than what IPCC's Fifth Assessment Report had indicated.Coastal nations and agricultural economies like India would be the worst affected, the report said, adding decline in crop yields, unprecedented climate extremes and increased susceptibility could push poverty by several million by 2050."The world cannot afford a warming of 2°C above the pre-industrial era. A 2°C warmer world will devastate economies and ecosystems and push hundreds of millions of people back into poverty."The goal of climate change now must be firmly fixed to 1.5°C to give the communities and nations a fighting chance to avoid the worst impacts of climate change. India must take the lead in creating a global coalition in this endeavour," said Bhushan.CSE said the report also makes it clear that the current level of climate ambition, as set out under the Paris Agreement, will lead to disastrous effects on the planet as it is not in line with limiting warming to even 2.0°C.With inadequate climate efforts, global warming is likely to reach 1.5°C between 2030 and 2052.If global emissions continue as per the commitments made under Paris Agreement, the carbon budget (the amount of CO2 that the world can emit) for 1.5°C warming will be exhausted by 2030, the CSE said referring to the report.In order to limit warming at 1.5°C, the world will have to reduce carbon dioxide (CO2) emissions by 45 per cent by 2030 from the 2010 levels and reach net-zero emissions by 2050, it said."Though it will be very difficult in the current global economic system to limit warming to 1.5°C, but it is not impossible. This will require acting on all fronts to rapidly reduce emissions by 2030."Without an active participation of the US, this will be impossible. In totality, how the rest of the world handles the climate rogue behaviour of the Trump administration will decide whether the world meets the 1.5°C goal or not," Bhushan pointed out.CSE said by refusing to endorse the findings of the IPCC's 1.5°C Report, the US has again given a clear signal that it would continue with its "climate regressive agenda", which includes obstructing the work of the UNFCCC and promoting fossil fuels like coal and gas."Considering the urgency to rapidly decarbonise, the world needs a 'Plan B', as the Plan A -- the Paris Agreement -- will push the world towards catastrophic warming."India must take the lead in forming a global coalition for a 1.5°C world to save poor and vulnerable populations across the world including its own,” Bhushan said.Narain said the focus must now be on how the world can build a coalition to support the massive transformation required to achieve the 1.5°C target.