Yogesh Punja used a mock climate change summit for high school students in Canberra on Wednesday to urge countries attending the global summit to "please save" Pacific Islands facing rising seawaters that threaten to inundate their homes.

Mr Punja said his country wanted a global target of maintaining a rise in temperatures below 2 degrees to be revised down to 1.5 degrees.

He described island nations like Fiji as a "canary in a cage" for a warming climate.

"We have had a number of simulations done to show what will happen to the planet if the temperature went up by 1.5 degrees," he said.

"If we only [aim for] 2 degrees, it becomes critical. I think by 2 degrees many of the Pacific nations will disappear.

"Our message to COP21 is look out, we may disappear – please save us."

Mr Punja said changing fish migration patterns meant communities were also becoming "economic refugees".

"You have to see through your own eyes how desperate these people are,' he said.

Mr Punja was among a number of delegates talking to 70 Canberra high school students as part of the Young Leaders Climate Conference at Telopea Park School.

The panel discussion included representatives from the European Union, the United States, China, France and Australia's Department of Foreign Affairs and Trade.

Aside from listening and asking questions of the panel, the group of teenagers discussed climate change and renewable energy and held their own mock summit, representing some of the major players heading to the Paris negotiations.

European Union ambassador to Australia Sem Fabrizi said he was impressed by the students' enthusiasm and their knowledge of the complexities of climate change.

"The future belongs to them and I think the students today are very aware of it," he said.

"There's an inter-generational duty to lead the next generation to a better place. The students have clear understanding that climate change ... isn't something vague, isn't something remote, isn't something that doesn't affect them."

Mr Fabrizi said the European Union had set a "very ambitious commitment" to climate action ahead of the Paris summit from November 30 – including reducing greenhouse gas emissions by 40 per cent between 2020 and 2030 – and hoped other countries would show similar ambition.

He said announcements, such as France and China's proposal to revisit the progress of any global climate pact every five years, helped create "the right political climate" for a successful summit.

Asked if Australia was doing enough to tackle climate change, Mr Fabriz said our country was "very much engaged in Paris, working very closely with us and sharing our own commitment to make Paris a successful outcome".

"It is a collective exercise and we have to ensure the agreement is applicable to all".

While Wednesday's students fell just short of negotiating a 2 per cent target among themselves, Canberra College student Egshiglen Chuluunhuu said the event had changed her view of climate change.

"It's kind of unnerving because we're going to be living in the world they [world leaders] are making decisions for. I think events like this really ease that worry because it empowers us and tells us that we do have a voice and we do have the power to influence these major decision-makers," the 16-year-old said.

"The example Australia sets is going to be really important for all of the nations around it – countries in the Pacific will all look to Australia."

UN Youth ACT president Claire Paton said Wednesday's event empowered younger Australians to engage in what could be a complex topic.

"Young people are really idealistic and that's one of the best things about young people, they go for the hardest option because that's the one they see as going to be more effective long-term," she said.

"I think a lot of people don't look at the younger generation as being engaged or understanding issues. A lot of them are passionate about taking a stand on climate change."