OSLO : The United Nations will seek ways to toughen environmental laws this week to crack down on everything from illegal trade in wildlife to mercury poisoning and hazardous waste.The UN Environment Assembly (UNEA), a new forum of all nations including environment ministers, business leaders and civil society, will meet in Nairobi from June 23-27 to work on ways to promote greener economic growth.“We often have environmental legislation that is well intentioned but is not effective,” Achim Steiner, head of the UN Environment Programme which will host the talks, told Reuters. Many countries sign up for environmental treaties but are often slow to ratify and fail to enforce them in domestic laws, on issues ranging from protecting animals and plants from extinction to outlawing dangerous chemicals or regulating hazardous waste.“Simply signing a commitment is one step, putting the finance, the technology, the laws in place are critical ingredients,” he said.The Nairobi talks will include a meeting of chief justices, attorneys general and other legal experts. They will seek ways to improve cooperation, speed up ratification of treaties and try to find models for domestic legislation.“Illegal activities harming the environment are fast evolving and growing in sophistication,” UNEP said in a statement. There was insufficient international coordination to catch crime gangs, from illegal fishing to loggers.Carroll Muffett, president of the Center for International Environmental Law in Washington, said “there are numerous pitfalls” for environmental treaties.One big drawback is that developed nations often fail to provide promised finance to help poor nations fight everything from toxic waste to illegal logging, he said.“Our experience has shown again and again that this financial support never comes through,” he said.And treaties face big hurdles even after they are negotiated. Last year, for instance, nations agreed a new convention to limit mercury, a heavy metal that can damage the human nervous system and cause liver damage and memory loss.So far the United States is the only nation to have ratified the pact, which needs 50 ratifications to enter into force.About 100 other nations including China and most industrialised states have signed - a declaration of intent to formally ratify the pact.“We anticipate to have the minimum 50 ratifications in two and a half years,” Steiner said. “That would be a very fast process.”Successes have included conventions such as the 1987 Montreal Protocol for protecting the ozone layer. Others have struggled, such as the 1997 Kyoto Protocol for curbing greenhouse gas emissions which only entered into force in 2005.The United Nations will also issue a report on ways to crack down on wildlife crime. Steiner said there was an “enormous increase” in illicit trade, from ivory to timber, with increased links to international crime syndicates and drug cartels.The UNEA, a forum agreed at an Earth Summit in Rio de Janeiro in 2012, marks a shift from a former system in which only 58 nations met yearly to discuss environmental problems.“It is a watershed,” Steiner said.