Fears about climate change are overblown and shifting weather patterns and rising sea levels should be considered an engineering problem, said the head of the world's largest oil refiner, ExxonMobil.

"The fear factor that people want to throw out there to say 'we just have to stop this,' I do not accept,"  Rex Tillerson, ExxonMobil's chief executive, said in a speech on Wednesday (June 27).

Tackling global poverty should have a higher international priority than reducing carbon emissions, because it would give billions of the world’s energy poor access to oil and gas supplies, in his view.

"They'd love to burn fossil fuels because their quality of life would rise immeasurably," he said.

"You'd save millions upon millions of lives making fossil fuels available to parts of the world that don't have it," he added.

Tillerson proposed adapting to the effects of climate change through engineering methods, rather than attempting to prevent them by eliminating the use of fossil fuels.

Humans had long adapted to change, he said, and governments should thus create policies to cope with the Earth's rising temperatures.

"Changes to weather patterns that move crop rotation areas around – we'll adapt to that. It's an engineering problem and it has an engineering solution," Tillerson said in a presentation to the US Council on Foreign relations in New York.

Tillerson's remarks came five days after Rio+20 summit in which leaders aimed at setting up goals for sustainable development to help the very people the oil executive mentioned.

People in the many of the world's poorest areas are expected to feel the harshest effects of climate change, including sea level rise, more severe storms, floods and droughts.

ExxonMobil, once one of the staunchest critics of climate change research, has acknowledged under Tillerson's leadership that human-made emissions have contributed to altering the planet's climate.

The company now supports taxing carbon emissions.

But the UN Intergovernmental Panel on Climate Change has emphasised the need for mitigation of global warming, including limiting climate-warming carbon emitted by fossil fuels like oil, along with adaptation to it.