“Today the climate is warming. The animals are disappearing. The rivers are dying and our plants don't flower like they did before.
“The Earth is speaking. She tells us that we have no more time.”
Ms Surui urged world leaders to adopt a different, faster path towards reducing carbon emissions and global warming.
“It's not 2030 or 2050. It's now,” she said, adding that a friend of hers when she was young was murdered for protecting the Amazon.
“Indigenous people are on the front line of the climate emergency and we must be at the centre of the decisions happening here.”
World leaders have made various new pledges to decrease emissions in the lead up to COP26, which is seen as being key to limiting global temperature rises to 1.5 degrees Celsius.
Young Samoan activist Brianna Fruean on Monday urged delegates at the summit to have “the political will to do the right thing, to wield the right words and to follow it up with long-overdue action”.
Ms Fruean said young Pacific islanders have been leading the way in the region in pushing for greater climate action.
“We are not just victims to this crisis. We have been resilient beacons of hope. Pacific youth have rallied behind the cry: 'We are not drowning. We are fighting',” she said.
Ms Fruean said when she was young she was taught the importance of language and told delegates of a proverb in Samoan culture that translates to “even stones decay, but words remain”.
“[It is] a lesson in knowing how words can be wielded, how text can change everything, how each word you use is weighted,” she said.
“[It is a lesson in] how switching one word or number could reframe worlds, how climate action can be vastly different from climate justice, how 2 degrees could mean the end, and 1.5 could mean a fighting chance.
“You all have the power here today to be better, to remember that in your meeting rooms and drafting documents are more than just black and white objects, to remember that in your words, you wield the weapons that can save us or sell us out.”
With just over 1 degrees of warming since the Industrial Revolution, the world has been seeing more extreme heatwaves, flooding, storms, and rising seas, placing island nations and First Nations cultures at particular risk.
Other speakers at the opening of COP26 on Monday included Britain’s Queen Elizabeth II and UN chief Antonio Guterres, the latter of whom said “we are digging our own graves” by not doing more to combat the climate crisis.