How many species could go extinct from climate change? It depends on how hot it gets.

Two Kea birds, Arthurs Pass South Island New Zealand. The species is listed as threatened in that country and climate change is among the reasons their numbers are in danger.

To consider how climate change could cause some extinctions, imagine a tiny mountain bird that eats the berries of a particular mountain tree.

That tree can only grow at a specific elevation around the mountain, where it's evolved over millennia to thrive in that microclimate. As global temperatures rise, both the tree and the bird will be forced to rise too, tracking their microclimate as it moves uphill. But they can only go so far.

Ivory tusks seized during an anti-smuggling operation are displayed during a Hong Kong Customs press conference on October 20, 2012 Officials travelling to Tanzania with Chinese President Xi Jinping went on a buying spree for illegal ivory, an environmental activist group has said. The delegation bought so much ivory prices in the local market soared, the Environmental Investigation Agency (EIA) said in a report. Tanzania rejected the report as "stupid nonsense". China said the allegations were "groundless". Conservationists say demand for ivory in China is fuelling poaching. In recent years, poaching has increased across sub-Saharan Africa, with criminal gangs slaughtering elephants for ivory. Tanzania is the largest source of poached ivory in the world, according to the EIA. 'Security checks averted' The EIA report cited a trader in Tanzania's main port city, Dar es Salaam, named as Suleiman Mochiwa, who met undercover investigators. He said that when the Chinese government and business delegation arrived, ivory prices in the local market doubled to $700 (£438) per kilo during the visit. Earlier this year China destroyed a large quantity of confiscated ivory for the first time "The [delegation]... used the opportunity to procure such a large amount of ivory that local prices increased," the report says. Investigators alleged that the Chinese buyers could take advantage of a lack of security checks for those in the country on a diplomatic visit.

Ivory destruction Despite efforts to destroy ivory, criminals are becoming more organised, ingenious and dangerous. "We have seen more and more organised crime networks moving into the wildlife trade," says Davyth Stewart from Interpol, the international intelligence agency. "Groups who have been traditionally involved in drug trafficking, fire arms and human trafficking are now moving onto wildlife." It's clearly not a fair match: conservationists pitted against criminal gangs. But the wildlife experts say it's a fight they have to take on. They have gathered at the Zoological Society of London to tackle how to halt the rapidly growing trade in animals. The backdrop to these crisis talks is bleak. Thousands of rhinos, elephants, tigers and others have been slaughtered, becoming part of an illegal market that's worth an estimated $19bn a year. Many criminals see it as low risk, high profit, says Mr Stewart. "There is a lower risk of apprehension, it's unfortunate but law enforcement has not invested the resources in attacking wildlife crime as it has in other crimes," he explains. "Even in courts the penalties are much lower. Just last year in Ireland, we saw two people arrested for smuggling rhino horns worth half a million euros. They received a 500-euro fine." Demand and supply John Sellar, the former chief of enforcement at Cites (the Convention on International Trade in Endangered Species), says the focus of the battle should be shifted away from conservation towards the issue of criminality. "It's about locking up the bad guys," he tells the conference.

Forest elephants in the Central African Republic have become a new target for poaching gangs. Men armed with Kalashnikov rifles have massacred 26 elephants in the Dzanga-Ndoki National Park in the Central African Republic, say conservationists. WWF reported the number of carcasses, quoting its sources in the region. Concern about what was happening in the park was raised earlier this week when it was said that ivory poachers were using a scientist's observation platform to shoot the animals. Elephants regularly gather at the Bai, a large clearing, to drink. Since the shooting, no elephants have been seen in the area, WWF reported. The Dzanga-Ndoki Park, a World Heritage Site, is located in the south-western corner of the Central African Republic (CAR), where it borders Cameroon and the Republic of Congo. It is described as a unique habitat for forest elephants in particular. CAR has witnessed increased levels of violence since the beginning of the year, and conservation groups like WWF withdrew their staff from the Bai are for safety reasons. On Monday, the conservation group issued a warning that a 17 armed individuals, some with heavy-calibre rifles, had entered the park and was heading for the Bai, known locally as the "village of elephants". By the time the armed men had left, the Bai was said to resemble an "elephant mortuary", WWF said. Jim Leape, WWF International Director General, added: "The Central African Republic must act immediately to secure this unique World Heritage Site.