Thousands of young people in Scotland joined millions of others as part of a global climate strike on Friday with marches held in Edinburgh, Glasgow and Aberdeen.
It is the latest action inspired by activist Greta Thunberg after a series of school strikes last year in a call to tackle climate change.
Currently the Climate Change Bill states Scotland's emissions should be cut by 70% by 2030 as progress towards net-zero emissions.
However the amendment advanced and co-signed by the party would see this increased to 75%.
Energy spokesman Liam McArthur MSP said: "The transition to a net zero country needs to be quicker. Early action to cut emissions is critical to stopping irreversible damage to our environment.
"As the placards say, there is no planet B.
"This is both a credible and ambitious proposal to increase Scotland's climate change targets.
"In order to achieve this enhanced 75% cut, many aspects of our lives will require nothing short of transformation.
"At the Liberal Democrat conference this week we set out exactly how we would respond to the climate emergency.
"Across the entire UK we need rapid expansion in renewable energy, to insulate tens of millions of buildings and to end the sale of new diesel and petrol cars by 2030.
"That is the scale of the response the planet needs now."
The Scottish Greens have also called for a change - but to 80%.
Environment spokesman Mark Ruskell said: "In the same way that the next 10 years will be critical to our future, this week is going to be critical for Scotland's response to the Climate Emergency.
"The SNP are hailing their target date of 2045 for reaching net-zero emissions as being world-leading, but it is already out of date.
"As we heard from leading scientists this week, the pace of change is picking up as governments drag their heels. By 2045, 16-year-old climate strikers who are worried about their future will be 42 years old.
"Scotland has a fantastic opportunity to play a leading role in this crisis, but we need to keep up with events.
"I have lodged an amendment to commit to an 80% reduction by 2030, which is what the experts and NGOs in Stop Climate Chaos are calling for.
"Other parties need to match our ambition to build a future for all through a Scottish Green New Deal, if we are to recognise the urgency of the Climate Emergency."
The amendments will be voted on when the Bill returns for the final stage of the parliamentary process next week.
In Edinburgh on Friday, tens of thousands of demonstrators marched from the Meadows to Holyrood Park next to the Scottish Parliament while chanting, singing and waving placards.
Ahead of the strike action, the Scottish Government said it is "leading by example" through its bold actions to address the climate emergency.
A spokesman said: "The global climate emergency and a Green New Deal for Scotland are at the centre of our Programme for Government.
"We are leading by example through bold actions. We are redoubling our efforts and we will end Scotland's contribution to global climate change by 2045."