"Climate change does exist, and if you don't believe it now, then by the time you do it will be too late."
So say two outspoken 10-year-olds who are determined to get civic leaders in South Australia's Murraylands thinking about the issue - and acting to prevent it.
Inspired by Greta Thunberg, the young Swedish activist who led an international strike by 1.4 million school students in March, Casey Taylor and Amity Bailey delivered their message to two local councils this week.
They pulled precisely no punches.
"Your generation is not looking after the world like you should," Casey said on Monday night, frowning at a circle of councillors mostly four or five times her age.
"You don't need to worry - you won't be around when the world is destroyed.
"But your grandchildren and great-grandchildren will be."
Their demands: that their local governments declare a climate emergency, symbolically recognising the urgency with which we all must act to limit the effects of climate change; and that councils encourage recycling, composting, tree-planting, renewable energy, and the use of reuseable containers for takeaway food - "all simple strategies that don't cost much but could save a lot".
"I'm trying my best - are you?" Amity asked.
"I'm scared for my very existence and you should be, too.
"When you go home tonight, think about what you will do to help us stay alive.
"We need out-of-the-box ideas to keep us going, and more importantly, to keep Earth going."
As an agricultural district at the bottom end of the River Murray, the Murraylands will likely be a very different place by the time the girls grow old unless the world turns away from its present trajectory.
The regional centre, Murray Bridge, will experience twice as many days above 35 degrees by 2090 if global carbon emissions cannot be brought under control, the Australia Institute found in March.
On average, rainfall would reduce by 22 per cent and the temperature would increase by 3.6 degrees by 2100, SA Climate Ready researchers warned last month.
Murray Bridge Councillor Mat O'Brien gave his unqualified support to the idea of a climate emergency declaration.
"I'm sorry we're at the point now, in this country, that we have to rely on our youth bringing this issue to the attention of our lawmakers," he said.
"I've got kids your age, and I worry about their futures.
"I'm really proud of you - keep going and we'll get there together."
Amity's mother Simone, a Mid Murray councillor, said her daughter's activism had made her examine her own priorities.
"I thought about my candidate profile; I said I cared about the environment," she said.
"I hear from ratepayers about rate rises and debts ... but it wouldn't cost a lot to do some of these things."
Other councillors defended their organisations' records in terms of installing solar panels, planting trees and so on.
If there were any climate change deniers present, they did not speak up.
Yet both the Murray Bridge and Mid Murray councils opted not to act too rashly, and to seek more information from staff about what an emergency declaration would mean in practical terms.
Hundreds of local governments around the world have already declared a state of climate emergency, including three others in SA.
Casey said any action could not come soon enough.
"Lots of people think that I am just a child who runs around with no worries," she said.
"Well, they're wrong.
"I have worries, lots of worries, about what the world is coming to."