In 2007, China became the world's biggest emitter of greenhouse gases. Since then, not only the EU and the US, but also developing nations such as the alliance of small island states have put the government in Beijing under pressure to adopt binding emission cuts.

At the 2009 climate summit in Copenhagen, China announced that it would reduce its carbon intensity – the amount of greenhouse gas emissions per unit of economic output – by at least 40% by 2020. Achieving this ambitious goal has become an overriding political priority for the Chinese government. The draft of its new five-year plan, which will be discussed by the National People's Congress in March, includes an environmental tax and other carbon-cutting measures.

The five-year plan also includes the most relentless dam-building effort that any nation has ever undertaken in history. If approved, this program would cut off the country's nose to spite her face. It would irreversibly destroy China's great rivers and biodiversity hotspots of global importance.

China already counts more dams within its borders than any other country. It has paid a huge price for this development. Chinese dams have displaced an estimated 23 million people. Dam breaks in the country with the world's worst safety record have killed approximately 300,000 people. Scientific evidence suggests that one particular project, the Zipingpu Dam, may have triggered the devastating earthquake in Sichuan of 2008. Dams have also taken a huge toll on China's biodiversity, causing fisheries to suffer and driving charismatic species such as the Yangtze River Dolphin to extinction.

As part of its low-carbon diet, the Chinese government plans to approve new hydropower plants with a capacity of 140 gigawatts over the next five years. For comparison, Brazil, the United States and Canada have each built between 75 and 85 gigawatts of hydropower capacity in their entire history. Achieving the new plan's target would require building cascades of dams on several rivers in China's south-west and on the Tibetan plateau – regions which are populated by ethnic minorities, ecologically fragile, rich in biodiversity, and seismically active.

As a harbinger of the new trend, the Chinese government recently announced that it would allow a dam cascade on the Nu River or Salween – a pristine river at the heart of a World Heritage Site – to be built. China's premier, Wen Jiabao, had stopped these projects in 2004 as a major concession to environmentalists. The government also agreed to shrink the most important fisheries reserve on the Yangtze River so that a new hydropower scheme could go forward.

The unprecedented dam building spree is being pushed by provincial governments and state-owned energy companies, which often pursue vested interests. In the past, these actors were kept in check by a coalition of environmental activists, journalists and government officials, who often managed to gain the ear of China's top leaders. This has changed since Copenhagen. International pressure to limit greenhouse gas emissions is the single most important factor behind the huge push for hydropower in China.

Climate change is the most serious environmental threat of our generation. Yet the international community should address this threat in a holistic way, without losing sight of other challenges to the planet's future. The world is losing biodiversity at an alarming rate. Rivers, lakes and wetlands have suffered more dramatic changes than any other type of ecosystem. Because of dam building and other factors, freshwater species have on average lost half their populations between 1970 and 2000, and more than a third of all freshwater fishes are at risk of extinction.

As the head of the UN Environmental Programme warned last year, it would be arrogant to assume that humanity can survive without biodiversity. We cannot sacrifice the planet's arteries to save her lungs. China not only has a moral obligation to participate in the fight against climate change. The country has also committed to protecting its ecosystems under the Convention on Biological Diversity. It deserves respect for trying to limit greenhouse gas emissions at a per-capita level which is much lower than what industrialised nations emit. World leaders should let the government in Beijing know that they don't want China to destroy her rivers and the rich biodiversity they support to reach her ambitious carbon goals.

• Peter Bosshard is the policy director of International Rivers, an international environmental and human rights organization.