The world cannot afford to wait any longer to make drastic cuts in greenhouse gas emissions, two new studies have shown, as the United Nations climate change talks in Warsaw enter their final stage.

The research, published in the journal Nature Climate Change, shows that delaying reductions in carbon dioxide output would result in faster global warming, and therefore be more difficult to counteract in future years. This contradicts the arguments that some climate sceptics have put forward that drastic cuts can be delayed until future years, because of the current "pause" in global temperature increases, and the finding by the Intergovernmental Panel on Climate Change that the climate may be slightly less sensitive to the impact of rising carbon levels than the previous highest estimates.

The authors found that as carbon dioxide concentrations in the atmosphere accumulate over time, "what happens after they peak is as relevant for long-term warming as the size and timing of the peak itself", and this would imply "sustained emissions reductions are necessary if warming is to be kept below any agreed limit".

Myles Allen, professor of geosystem science at Oxford University, lead author of one of the studies, said: "Unless we assume the long-suffering taxpayers of the 2020s somehow manage to compensate for continued procrastination now, peak carbon dioxide induced warming is increasing at the same rate as emissions themselves – at almost 2% a year – which is much faster than the observed warming."

This means, he said, that further delay would be dangerous. "If we were aiming in 2010 to limit warming to 2C, a delay of only five years has already cost us two-tenths of a degree if we make the same effort starting in 2015. That is equal to the observed warming since the early 1990s."

The other study examined "short-lived climate pollutants" (SCLPs) such as methane and soot. Cutting these substances can reduce the immediate impact of warming, and there is a major international initiative under way to reduce the quantity of these into the environment. Substantial cuts could reduce projected warming by as much as 0.5C, according to some estimates, which has led some to suggest that we should concentrate on reductions in SCLPs while finding ways to reduce carbon in the future.

The paper, also led by Oxford University, found that SCLP emissions in any decade "only have a significant impact on peak temperature under circumstances in which carbon dioxide emissions are falling". This means that while swift action on SCLPs "might potentially buy time for adaptation [to the effects of climate change] by reducing near-term warming", over the longer term - that is, in more than a decade's time - those reductions need to be accompanied by strong action on carbon emissions to continue to dampen down temperature rises.

David Frame, a co-author of the paper, of the Victoria University of Wellington, New Zealand, said: "We show that taking action today on emissions of these SLCPs will have relatively little impact on peak warming unless carbon dioxide emissions are reduced at the same time. So action on these other pollutants does not buy time to delay action on CO2."