China and Canada, which worked together to broker a landmark global deal to protect nature in December, now need to use their joint leadership to build momentum and help countries meet biodiversity goals at the national level, green groups say.
At the COP15 UN biodiversity summit, about 195 countries agreed ambitious targets, including conserving at least 30% of land and oceans by 2030, while respecting the rights of indigenous peoples.
Last month's talks were led by China but held in Montreal, due to Beijing's challenges in curbing the spread of COVID-19.
The new "Kunming-Montreal Global Biodiversity Framework" - delayed by the pandemic and slow-paced negotiations - was welcomed by conservationists. But many remain wary of unmet nature pledges previously made by governments.
"Now we've managed the 'easier' part at COP15, the hard work of implementation should immediately begin," said Li Shuo, a policy advisor at Greenpeace China.
"China and Canada, as the parents of the deal, should keep injecting momentum into the global nature protection agenda in 2023," he added in an interview.
People around the world depend on nature - from oceans to rainforests - to supply them with clean air and water, and to regulate rainfall that is vital for growing food crops.
And because plants absorb planet-heating carbon dioxide to grow, strengthening conservation efforts is widely seen as one of the cheapest and most effective ways to slow climate change.
But forests and other ecosystems are still being destroyed, often to expand agriculture and production of commodities such as palm oil, soy and beef, to feed a growing global population.
Years of diplomatic tensions between Canada and China ahead of the two-week COP15 summit led to doubts over whether the two governments could land a global nature deal, similar to the 2015 Paris Agreement on climate change.
But Greenpeace's Li said their coordination at the final negotiations in the Canadian city of Montreal - the seat of the UN biodiversity secretariat - defied expectations.
"Both countries set a good example of nations putting their political differences aside for the global environmental agenda," he said.
"Collaborating further in the implementation ... will not only enhance their joint legacy but help improve their bilateral relationship," he added.
POWER OF 'FEAR'
The previous global biodiversity accord adopted in 2010 in Aichi, Japan, set 20 targets to stem biodiversity loss by 2020, but none of those were fully met.
While Aichi helped galvanise action by many countries, governments ultimately did far too little to stop the destruction of ecosystems and species, said Susan Lieberman, vice president of international policy at the Wildlife Conservation Society.
Marco Lambertini, special envoy for WWF International, said past nature deals had been struck when awareness of the threats to biodiversity was limited - but that has changed.
Evidence of the damage caused by human activities is now overwhelming, and there is growing understanding of how the degradation of nature affects plants, animals and our own lives, be it health or the economy, he added.
"I grew up in a society where people were looking at the destruction of nature as something to be sad about," Lambertini said.
"Now people are looking at (it) as something to be worried about. Fear is probably the most powerful evolutionary pressure," he added.
The Montreal nature deal includes more ways to measure progress and hold governments accountable for their promises than previous agreements, he said.
The only Aichi target that was close to being achieved, he noted, had measurable figures - protect or conserve 17% of all land and inland waters and 10% of the ocean by 2020.
The Montreal pact, in addition to the 30% conservation goal, also contains a pledge to restore at least 30% of degraded land, inland waters, and coastal and marine ecosystems by 2030.
But with less than eight years to meet this decade's COP15 targets, countries must immediately start preparing their national biodiversity plans, which are due to be submitted in 2024, said Toerris Jaeger, executive director of the Oslo-based Rainforest Foundation Norway.
"If they collectively fall short of the COP15 targets, the plans need to be further updated and ambitions increased accordingly," he added.
The need for more financing from rich countries to help poorer nations meet the new targets agreed at COP15 was a sticking point in efforts to hammer out the biodiversity pact.
The Montreal talks ended with some drama as the final deal was passed following objections from the Democratic Republic of Congo, which later appeared to downgrade its stance to "reservations" on financing and resource mobilisation.
The success of the COP15 deal will depend on sustaining political pressure and ensuring donors - both governments and philanthropists - deliver on their financial pledges, said Charles Barber, a senior biodiversity advisor at the World Resources Institute, a US-based think-tank.
Combining efforts to boost action and funding for climate, forest and biodiversity protection will be important, he added, pointing to a rainforest summit planned for March to be led by French President Emmanuel Macron and Gabon President Ali Bongo.
WWF's Lambertini said the COP15 goal of raising $200 billion per year in biodiversity funding is achievable because - unlike government pledges made under U.N. climate deals - COP15 finance will come from a wide range of sources, both private and public.
But, he cautioned, the aim of reducing harmful subsidies by $500 billion per year, such as support for intensive agriculture, may not be achieved by 2030 as changing economic models will require efforts beyond environment ministries.
Businesses, meanwhile, must start factoring nature into their decision-making at all levels, as they are already doing with climate change, said Linda Krueger, director of biodiversity policy at The Nature Conservancy.
"We can't waste time or momentum - implementation has to start immediately," she emphasised.