There's a strange smell coming from your kitchen, and you finally trace the scent to its point of origin: the fridge. You dig through reusable containers full of mouldy food, toss the wilting lettuce into the compost bin, and are too afraid to open the sour cream leftover from a nacho night held months ago, so you toss the whole thing into the garbage.

This is food waste — and it's contributing to climate change.

The Intergovernmental Panel on Climate Change (IPCC) released a report Thursday, entitled Climate Change and Land, that found better land management use — from forests to agriculture — would play a significant role in mitigating climate change.

But the authors also noted that tackling food waste is a factor that could help limit warming to 1.5 C to 2 C, the point where we will be unable to adapt to the worst effects of climate change.

Reducing food loss and waste can, in turn, lower greenhouse gas emissions for an obvious reason: Less waste means less land is needed for food production.

The IPCC report notes that roughly 25 to 30 per cent of total food produced annually is lost or wasted — and that has consequences. From 2010 to 2016, global food loss and waste contributed eight to 10 per cent of human-caused GHG emissions.

Waste from land to homes

Not all the waste comes from households; much of it comes from another source: Farms.

That's why the report's authors suggest that improved harvesting methods, on-farm storage, better packaging and education can significantly reduce agricultural food waste.

Together with these improvements, as well as overall improvements to land use and the reduction of fossil fuels, the report's 107 authors (who come from 52 countries) conclude that humanity will greatly benefit across the board.

A worker dumps pre-consumer food waste, which is fed to black soldier fly larvae, at the Enterra Feed Corporation in Langley, B.C., on March 14, 2018. (Ben Nelms/Reuters)

"Food waste is an enormous source of greenhouse gases. Every one of these choices adds up collectively to either increasing or reducing greenhouse gases," said Werner Kurz, co-author of the report and a senior research scientist for Natural Resources Canada.

"And people need to be aware and learn how their choices contribute to the problems that we face."

If we fail to take such steps, the authors note the planet could warm beyond that crucial 1.5 C or 2 C.

"Farmers can and must do important things. Eaters can and must do important things. And everyone who manages food can and must do important things," said Dianne Saxe, a former environment commissioner for Ontario who was not involved in the report. "And if we do them together, we have big synergies available."

What we can do

While better land management is the big picture, there are changes that can be made on an individual basis.

The World Wildlife Fund suggests a few steps for preventing food waste at home , including: planning ahead and buying only what you need; freezing food; and being "creative" with leftovers and using what you have.

It may not feel as though small choices can make much of a difference in a global issue as serious as climate change, but Kurz said every action counts — and will continue to count as we move forward.

"For the first time in humanity, we have to globally co-operate over multiple generations, because this isn't going to be solved in a single generation," he said.

"Every degree matters, every tonne of CO2 matters and every day matters."