Humanity’s greenhouse gas emissions have been building up in the atmosphere and warming the planet for the past 150 years, dragging us into the uncharted Anthropocene, or age of man. Almost all of the planet's tropical mountain glaciers have retreated or disappeared in recent decades, including those in the South American Andes, Asian Himalaya, and African Rwenzoris.
The resulting meltwater is finding its way into the oceans. Globally, they are rising at an average of 3.5 millimetres per year – roughly twice the rate seen during the 20th Century. Sea levels are expected to rise by around 2.3 metres (7.6 feet) for every 1C of warming in the coming decades, according to a study published by scientists at the Potsdam Institute for Climate Research last month. Most of the rise in the past decade was thanks to thermal expansion – at higher temperatures the water takes up a greater volume because its molecules move about more. Now however glacial melt has overtaken thermal expansion as the leading cause of rising sea levels.
At the poles, change is underway of a magnitude so extreme that Earth hasn’t experienced its like for over 10 million years. The Arctic is warming at least twice as fast as anywhere else on the planet. One estimate suggests future average global warming of 2-3C, for example, would mean Arctic warming of 6-8C. This is partly because of the hot southerly winds bearing soot pollutants converging on the region. These particles absorb the sun’s rays and when they land on the surface attached to snowflakes they darken it and speed up melting.
In Nepal, habitat loss and hunting have reduced tigers from 100,000 a century ago to just 3,000. The global loss of species is even worse than previously thought, the London Zoological Society (ZSL) says in its new Living Planet Index. The report suggests populations have halved in 40 years, as new methodology gives more alarming results than in a report two years ago. The report says populations of mammals, birds, reptiles, amphibians and fish have declined by an average of 52%. Populations of freshwater species have suffered an even worse fall of 76%.
The world's 100 most distinctive and endangered birds have been determined. Scientists in the UK and US chose the birds based on their rarity, but also how distinctive their appearance, behaviour and evolutionary history was. The list of birds contains several of the world's largest and most striking, as well as other unusual species threatened with extinction. Included are the tooth-billed pigeon, known as the little dodo, the Philippine's eagle and a type of kiwi. Scientists at the Zoological Society of London (ZSL), UK and Yale University in New Haven, Connecticut, US created the list as part of the EDGE of Existence programme, which seeks to document the most uniquely vulnerable species on the planet. Details of the exercise are published in the journal Current Biology. 
Giant ibis. The giant ibis stands tall at the top of the list At number one is a bird called the giant ibis. The largest member of the ibis and spoonbill family, the giant ibis stands over a metre tall, weighs 4.2kg and is the national bird of Cambodia. Despite this, fewer than 230 pairs remain. As well as being more distantly related to other members of its family, the giant ibis is expected to further decline in numbers due to habitat destruction and the predation of its eggs by mammals.
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