* Green groups lost first round
* Part of wave of other climate court cases worldwide
* Case runs to Nov. 14
By Nerijus Adomaitis
OSLO, Nov 5 (Reuters) - Green groups will try to convince a Norwegian appeals court on Tuesday that the government has violated the constitution by granting oil firms exploration rights in its Arctic waters.
Greenpeace and Norway's Nature and Youth group filed a complaint against the Norwegian state in 2016 in a lower court to seek to end Arctic oil drilling, but lost in 2018.
The case is part of an emerging branch of law worldwide where plaintiffs try to enlist a nation's founding principles to limit global warming.
A win in Norway could set a precedent for other climate cases globally and have an impact on exploration in Western Europe's biggest oil and gas producer, the plaintiffs say.
"If anything, our case stands stronger than before," said Frode Pleym, head of Greenpeace Norway, citing the latest U.N. climate reports and increased public opposition to Arctic oil exploration.
"Norway must stop looking for all oil ... We do think that (the verdict) would have an impact on Norwegian policies," he told Reuters.
They base their case on article 112 of the constitution, which guarantees every person's right to a healthy and sustainable environment, also the right of future generations.
They also point to Norway's decision to continue exploration for oil and gas which, they say, contradicts its commitments under the Paris climate agreement.
Oil and gas amount to more than half of the value of Norway's exports and helped build its $1 trillion sovereign wealth fund into the world's largest.
In a sign the government continues to take the case seriously, Attorney General Fredrik Sejersted will defend the state in the appeal, as he did in the first round.
Last year, the Oslo District court said the 23rd licensing round that granted offshore exploration rights to companies including Equinor and Chevron was legal. Since the lawsuit was filed, Chevron has exited Norway.
In written submissions to the court seen by Reuters, the government will argue that the licences were "clearly not in breach of principles of international law, neither under environmental and climate law nor according to traditional human rights".
The energy and oil ministry directed requests for comment to the Attorney General, who declined comment before the beginning of the appeal.
Two organisations - the Grandparents Climate Campaign and Friends of the Earth Norway have joined the side of the plaintiffs for the appeal.
The oil industry accounts for a quarter of Norway's domestic greenhouse gas emissions, which stood at 52 million tonnes last year, up 1% compared with 1990, according to Statistics Norway. (Editing by Gwladys Fouche Editing by Robert Birsel)