When they first warned more than 30 years ago that human activity could create an enhanced greenhouse effect, scientists hoped it would lead to decisive action to lower fossil fuel emissions.

Instead, levels have continued to rise to a point most scientists agree that climate change accelerated by fossil fuel emissions is changing the weather and intensifying storms.

"Plan A was the hope governments would step up and social movements would be powerful enough to put pressure on governments," University of Adelaide Law School Associate Professor Peter Burdon said.

"But that hasn't happened, so Plan B is to try the courts," he said.

Across the world a shift towards climate change litigation is gathering steam as low-lying island countries and even United States' cities take aim at governments and big oil companies for failing to act proportionately on emission reductions.

One of the most recent cases involves 21 teenagers in the US state of Oregon, who have been given judiciary permission to sue the federal government for failing to uphold their constitutional rights.

"They assert that the actions of the [US] government and their delays and failure to take meaningful action against climate change has violated their generation and their constitutional rights to life, liberty and property," Professor Burdon said.

"They've gone through several layers of hearings and at every stop, the government has sought to throw it out, and have been joined by companies like ExxonMobil and Chevron, but it was decided they had a legal case and it can be heard."

Elsewhere in the US, cities such as San Francisco and Oakland have filed lawsuits against big oil and gas companies to pay damages caused by rising seas, while in the Netherlands, Friends of the Earth have threatened litigation against Royal Dutch Shell if it doesn't bring its business in line with the Paris Agreement within eight weeks.

It follows a landmark ruling in the Hague District Court during 2015, which forced the Netherlands government to reduce emissions by 25 per cent by 2020 after it was found to be breaching a duty of care.

Modelling has predicted cities like Brisbane are on track to lose large sections to the ocean by 2100. ( Supplied: Coastal Risk Australia 2100 )

Drawing similarities with big tobacco cases

The Hague court accepted there was a class of greenhouse gas emissions caused by human activity (anthropogenic) and therefore no dispute whether the government was contributing or causing a degree of climate change.

Professor Burdon said accusing big oil and gas companies and governments of contributing to climate change rather than blaming them outright was a similar approach to those who fought big tobacco in the past.

"That was precisely what big tobacco did in the case against them, because how do you prove that your smoking led to this particular type of cancer?" he said.

"Attribution science, drawing the link of causality between what a company did and the effect you're experiencing, is something that government and fossil fuel companies can delay or run counter arguments against.

"But if you argue that their actions perhaps didn't cause a storm event or bushfire, but exacerbated it and increased its intensity, that, I think, is a stronger argument."

The Netherlands decision of 2015 was achieved by 886 individual co-plaintiffs represented by the Urgenda Foundation, which was subsequently "inundated with requests for assistance to commence like litigations around the globe".

The National International Law Association (NILA) warned at the time that it had potential for a "significant ripple effect for establishing climate liability around the world and in Australia".

It acknowledged, however, that the Netherlands have a civil system and a constitutional requirement to keep the country habitable and to protect and improve the environment, as does the US.

"Australia has a common law system and any case must be founded first on an appropriate course of action," a NILA spokesperson said.

"There is no similar express constitutional requirement."

Low-lying countries with Australia in their sights

Australia's carbon footprint per capita is among the highest in the world — 15.4 tonnes during 2014 compared to 16.5 tonnes in the US, according to World Bank figures.

This means its citizens punch well above their weight even if the country's overall emissions are comparatively low when compared to the likes of the US, Russia and China.

The Pacific island country of Palau has sought an advisory opinion from the International Court of Justice about whether it has a case against other countries for failing to prevent, reduce or control the risk of environmental harm to other states.

It follows threats by nearby Tuvalu in 2002 to take Australia and the US to court for failing to act on emissions.

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Watch Duration: 45 seconds 45 s Locals say tidal flooding events have become more frequent on Marshall Island due to rising sea levels.

Federal Environment Minister Josh Frydenberg did not answer if he was concerned by litigation manoeuvres taking place overseas but said Australia's emissions per capita and per GDP were now at their lowest level in 28 years and were on track to beat its "2020 target by 294 million tonnes".

"We have ratified the Paris Agreement alongside 170 other countries and we are committed to a strong but responsible 2030 target of 26 to 28 per cent below 2005 levels, which will see a halving of our emission per capita," he said.

Environmental Defenders Office Queensland chief executive officer Jo Bragg said the nation's governments were taking a "huge risk" if they failed to implement measures that effectively protected or "cushioned Australian citizens from the reasonably foreseeable impacts of climate change".

"While we have not seen the breadth or number of civil suits in Australia that have been launched in other countries, government must not be complacent and assume such suits will not be run," he said.

"Certainly, over the last seven years there have been a number of legal challenges by community groups to government decision-making approval of major thermal coal mines in Queensland and New South Wales."

People from Pacific Island nations want climate change action. ( Te Mana: Litia Maiava )

Secondary effect of tarnishing reputations

Professor Burdon pointed out that climate change litigation often had the secondary effect of causing reputational damage to big oil companies.

"It's well documented now that Exxon have known about the risk that their work and their extraction processes have created for climate change for more than 30 years," Professor Burdon said.

This includes media reports in 2015 about an email written by Exxon's former climate expert Lenny Bernstein — in response to an inquiry by Ohio University — that revealed the company was aware of carbon dioxide's contribution to climate change nearly 40 years ago.

ExxonMobil runs several oil platforms in Bass Strait off the Victorian coast. ( Supplied: ExxonMobil )

Mr Bernstein wrote to the university's Institute for Applied and Professional Ethics director that Exxon first became "interested in climate change in 1981 because it was seeking to develop the Natuna gas field off Indonesia".

"Exxon needed to understand the potential for concerns about climate change to lead to regulation that would affect Natuna and other potential projects," he wrote.

"They were well ahead of the rest of the industry in this awareness; other companies, such as Mobil, only became aware of the issue in 1988 when it first became a political issue."

Professor Burdon said that bringing a suit against an organisation like ExxonMobil was also about "hoping you can cause some reputational damage to them, or it could be about trying to halt or delay a project that they're trying to get through".

Both BP Australia and the Australian Petroleum Production & Exploration Association declined to comment on the likelihood of facing law suits in Australia.

But even if the evidence supporting anthropogenic climate change continues to increase, Professor Burdon said the primary success of court action will depend on a judge and whether or not they were the right person to understand the science.

"While they strive to be neutral, the judges are still human beings with their own political views and ideas," he said.

"It's about trying to get the perfect storm, get the right case with the right set of data with a judge who's open to the argument."