In some respects, the Volkswagen emissions scandal could not have come at a worse time.

Unfolding two months before the kick off of the historic COP21 climate summit slated for next month in Paris, the revelations that the car giant cheated emissions tests reinforced long-held suspicions among some skeptics that the private sector’s buy-in on climate change was superficial.

The 2015 Climate Change Survey produced by GlobeScan and SustainAbility reveals that international sustainability experts continue to view the contribution of business as modest.

However, if we are to see meaningful long-term progress, national governments as well as the private sector will have to step up, as the two institutions will be critically important for the implementation of the post-COP21 framework.

For the 2015 survey, over 600 global sustainability experts representing business, government, NGOs and academia were polled about their expectations for the COP21 meeting, asking respondents to share insights about the importance of various actors and climate strategies post-2015.

Unilever, Tesla, IKEA, Google and GE are considered to be leading the way, mostly as a result of their leadership on renewable energy, technological innovation, commitment at the executive level and advocacy efforts.

Given repeated lack of progress on climate change in recent years, and in light of increasingly stark evidence of ongoing climate disruption, there is a palpable sense of frustration toward government.

When asked which institutions had made the biggest contributions to advancing climate change solutions over the past five years, just 14 percent of the experts polled said that national government made a “large” or “very large” contribution — the lowest rating of any institution.

The best perceived contributions came from scientific institutions, NGOs and the UN.

Experts are reserved about the private sector’s track record in recent years – they are more likely to  say that business has done very little or nothing at all than view the contribution of corporations as  significant.

From those businesses that do take action on climate change, technology and consumer companies are seen as doing the most.

Unilever, Tesla, IKEA, Google and GE are considered to be leading the way, mostly as a result of their leadership on renewable energy, technological innovation, commitment at the executive level and advocacy efforts.

The private sector will have to do significantly more post-2015 for the international community to move the needle on climate change, the survey indicates. While governments have grown accustomed to being in the hot seat, many companies are still getting used to the idea that they, too, have an obligation to tackle global warming.

According to 86 percent of experts, the role of the private sector in the implementation of the post-Paris framework will be “important” or “very important.”

Switching to renewable energy and reducing emissions in the supply chain are seen as the most effective ways for business to contribute.

While the role of scientific institutions continues to be seen as important, we are seeing a change in the perceived effectiveness of climate change strategies.

Though economic and regulatory approaches remain the most agreed upon ways of achieving change, survey responses indicate a shift in emphasis from science to cooperation and diplomacy. As for the effectiveness of economic
instruments, respondents are clear — the governments should take action to abolish subsidies for the fossil fuel industry and introduce taxes on greenhouse gas emissions.

Overall, a cautious sense of optimism prevails ahead of the Paris conference. An overwhelming 92 percent believe that a pact of some sort will be reached. While only 32 percent of respondents are confident that the COP21 accord will have binding powers, expectations are high that the December summit will put the international community back on track to containing climate change.

The success of post-2015 climate action will not be possible without a more widely shared collective effort and deeper involvement of all actors. However, the efforts of state leaders and corporations will be paramount.

The stakes are high and the journey ahead is long — the time to act is now.