Trump's Paris move 'hardly game over' - scientist

A Kiwi climate scientist says Donald Trump's withdrawal of the US from the Paris climate accords is a step backwards, but not game over for the climate.

The US President made the announcement at the White House on Friday morning (NZ time), saying he could not in "good conscience support a deal that punishes the United States".

The move has been condemned widely, even by oil companies including Shell, ExxonMobil and BP, but scientists say there's still time to halt runaway global warming.

"Trump pulling out may just encourage the rest of the world to do more," said Prof James Renwick of Victoria University's School of Geography, Environment and Earth Sciences.

"The US is pulling back from global leadership and other nations will step in to take over. This move may, in fact, signal the start of China's real dominance of international affairs."

Environmental lawyer Al Gillespie of the University of Waikato has an opposing view. He says with the US ending funding towards a "global green fund" established by the Paris Agreement, other countries might pull out too.

"This is unprecedented. This is the mother of all agreements, the biggest deal in the world. It took 25 years. And to back out now - it goes to the heart of our future."

Cities go it alone

Prof Renwick said individual US cities and states will continue to push for reduced emissions. New York Mayor Bill de Blasio has said his city will honour the 2015 agreement.

In his speech Friday morning (NZ time), Mr Trump said he was elected to "represent the citizens of Pittsburgh, not Paris". The Mayor of Pittsburgh responded on Twitter, saying 80 percent of voters in the city voted for Hillary Clinton and the city would "follow the guidelines of the Paris Agreement for our people, our economy & future".

Mayors and Governors from across the US have said they'll form a new group, the United States Climate Alliance, in response to Mr Trump's move.

"This administration is abdicating its leadership and taking a backseat to other countries in the global fight against climate change," said New York Governor Andrew Cuomo. 

Other states to sign up so far include Washington and California.

Surprising, if expected

Political scientist Assoc Prof Bronwyn Hayward of the, University of Canterbury said she was "shocked" to hear Mr Trump's comments about climate change, even though his move was widely signalled ahead of time.

"It feels surreal to be listening to Trump's announcement as I am packing to leave tonight for the author meeting on the Special Report for the Intergovernmental Panel on Climate Change about how to achieve the objectives agreed in Paris to limit global warming to 1.5degC above pre-industrial levels."

She says no new jobs are likely to be created in fossil fuel industries, and the President is likely to face increasing pressure to his already tenuous grasp on the leadership of the free world.

"The leadership vacuum allows space for a new generation of younger world leaders and city and state governments to position themselves as offering new vision, and many like the state of California are already significant global leaders in addressing climate change."

Prof Gillespie says China will be the one to fill the international breach.

"There's a lot of money to made it stopping climate change. They are charging ahead with developing new eco-technology."

New Zealand can't be seen to be too smug over Mr Trump's withdrawal however, says Prof Gillespie.

"Most countries reduce carbon domestically. We buy carbon credits instead. We avoided making hard targets - we are at the back of the pack.

"We will make some concerned words, but our government won't be that upset. It makes them look worse than we do."

Mr Trump has previously called global warming a Chinese "hoax".