The revelation comes as representatives from 160 countries, including Australian Environment Minister Greg Hunt, prepare to sign the agreement in Paris later today.
PNG ambassador Charles Lepani told the ABC his country was paying the consequences for Australia's other economic activities.
"The consequences of coal, for instance coal mining, will impact us tremendously going forward," Lepani said.
The said he would like to see the Australian coal mining industry slowed down.
"Yes, we have made that point clear to your government and your leaders," he said.
The federal government says it is committed to implementing its pledge to lower emissions by 26 to 28 per cent on 2005 levels by 2030.
A gathering was organised in Canberra last night of senior diplomats from other countries signing the Paris Agreement to celebrate the milestone.
US Ambassador John Berry said the agreement was "a testament to human tenacity".
China's charge d'affaires Cai Wei said it was important countries stick to their Paris pledges.
"We will honour what we have promised, despite enormous downward pressure on the Chinese economy," he said.
But Lepani sounded a note of caution at the gathering.
"We are very happy in fact that some semblance of international action has been achieved in Paris. I say semblance, as we have to see serious action going forward."