The G20 nations play a critical role in the fight against climate change, as they are responsible for about 77% of global greenhouse-gas emissions (2023). The Paris Agreement aims to address this by encouraging increasingly ambitious nationally determined contributions (NDCs) every five years. To date, 166 out of 194 Paris Agreement parties have pledged to significantly reduce their emissions.
Despite these commitments, the 2023 United Nations Environment Programme Emissions Gap Report shows that a significant implementation gap remains. The G20 nations are collectively projected to fall short of their updated NDC targets by about 1.2 gigatonnes of CO₂-equivalent per year by 2030. Some countries—including the United States, the United Kingdom, the EU27, Japan, Australia, and Indonesia—have made progress in reducing emissions, with many having already peaked and invested in renewable energy and efficiency measures. A growing number of G20 nations have also pledged to reach net-zero emissions by mid-century.
The window for implementing carbon-reduction goals is narrowing. Current estimates indicate that global emissions would need to fall by roughly 42% by 2030 to remain on track for limiting warming to 1.5°C. Achieving this would require unprecedented international cooperation, and sustained reductions would support the path toward global net-zero emissions around 2050.
The Emissions Gap Report highlights four key areas for reducing emissions: reducing energy demand, decarbonizing energy supply, decarbonizing land use, and reducing short-lived climate pollutants.
Decarbonizing the energy supply has seen the most progress to date. Countries will need to continue increasing the share of renewable energy—such as wind and solar—within their power grids and further explore solutions including electric vehicles and carbon-capture technologies. Industrial production will also need to transition toward low-carbon or zero-carbon processes by mid-century.
Decarbonizing land use is another important pathway. Improvements in farm energy use, reduced transport and packaging footprints, better soil management, lower fertilizer use, and reduced food waste can all contribute to lowering emissions. Supporting local produce and farming practices that prioritize soil health and responsible resource use can also play a role.
Short-lived climate pollutants—such as methane, which has a relatively short atmospheric lifespan but a strong warming effect—can influence near-term climate outcomes. Reducing methane emissions is identified as a key component of achieving net-zero goals. Reducing energy demand can also be supported through more efficient building practices, retrofitting existing structures, and adopting energy-efficient technologies. While about 3.5% of buildings would need to be retrofitted annually, current rates remain below 1%.
In Canada, greenhouse-gas emissions have increased since 1990, and the country did not meet its earlier 2030 reduction target. As of December 2024, Canada has set a new target: a 45–50% reduction below 2005 levels by 2035. Canada is already experiencing the effects of climate change, including warmer winters, more extreme weather events, shrinking Arctic sea ice, and projections of longer ice-free periods in the Baffin Bay and Beaufort Sea.
Scientists worldwide continue to emphasize that countries must work together and reduce greenhouse-gas emissions rapidly and significantly to avoid a projected 2.8°C warming by the end of the century. Warming at this scale could accelerate ecosystem decline, increase extreme weather events, heighten conflict, and worsen food insecurity. The narrowing window to enact meaningful change underscores the urgency of the situation as the climate crisis intensifies.