The obstacles facing this weekend’s historic global climate change accord were thrown into relief on Sunday night when businesses and government officials downplayed the impact of the deal and US Republicans underlined their opposition.  The Paris agreement, which requires all countries to regularly publish plans to deal with global warming, has been hailed by international leaders as a turning point after more than 20 years of effort to make this century the last to be powered by fossil fuels.   German chancellor Angela Merkel said the deal was “the first time that the entire world community has obligated itself to act — to act in the battle against global climate change”, while Pope Francis also praised the “concerted effort and generous dedication” of those involved. It was adopted by nearly 200 nations.  But coal and oil industry executives shrugged off any suggestion the new agreement sealed in Paris on Saturday night would have any immediate impact on their businesses.