Pacific nations are pushing for big cuts to greenhouse gas emissions from the shipping industry at a conference in London.
More than 100 countries are meeting at the International Maritime Organisation to try and agree on a new emissions policy.
The shipping industry generates more than two percent of global CO2 emissions but it's projected to increase rapidly.
The industry was also exempted from the Paris Climate Change agreement.
Marshall Islands environment minister David Pauls said for Pacific countries, it's essential shipping companies get on board to help fight global warming and sea level rise.
"We can talk about the bottom line, we can talk about corporate profit, we can talk about economic development and economic prosperity. But, if you're very survival is at stake, nothing else matters, right?"
The big shipping nations such as Panama and Brazil argue their economies could be damaged if action to cut emissions is too hasty.