Hundreds of landmarks from Paris' Eiffel Tower to Sydney's Harbour Bridge to the Seattle Space Needle dimmed their lights on March 28, as people around the world mark Earth Hour with candlelight and barbecues.

The 60-minute annual campaign organised by conservation group WWF encourages citizens, communities, businesses and organisations to switch the lights off for an hour from 8:30pm to highlight the plight of planet Earth.

Now in its ninth year, Earth Hour’s goal is not to achieve measurable electricity savings, but to raise awareness of the need for sustainable energy use, and this year also to demand action to halt planet-harming climate change.

“Over 170 countries and territories have already confirmed their participation; more than 1200 landmarks and close to 40 UNESCO world heritage sites,” Earth Hour head Sudhanshu Sarronwala said.

These range from the Christ the Redeemer statue in Rio de Janeiro, the Acropolis in Athens, Edinburgh Castle, Big Ben, Ecuador’s Quito historical centre and New York’s Times Square.

Earth Hour 2015 takes place just months before UN member states are meant to sign an ambitious pact in Paris in December to limit galloping global warming, and just days before a loose end-March deadline for “those parties ready to do so” to submit their carbon-curbing pledges.

From a small, symbolic event held in Sydney in 2007, Earth Hour has grown to a global campaigning event with a festive twist.

This year will include a glow-in-the-dark Zumba party in the Philippines, a co-ordinated candlelit dinner in Finland billed as the world’s largest, restaurant dinners by candlelight in London, and a power-generating dance floor to light up the Eiffel Tower after its hour-long sleep, said WWF.

The organisers published a list of ideas for individual participants, which included barbecuing instead of stove cooking, a candle-lit street party or a picnic under the stars.

An estimated nine million people in 162 countries took part in Earth Hour last year, according to the WWF, of whom 85 per cent “said that they felt inspired to do more to protect the planet, such as making small changes to live more sustainably and reduce their impact on the environment.”



Even a short email is estimated to have a footprint of 4g of CO2e (gCO2e) – including greenhouse gases produced in running the computer, server and routers and a part of their manufacture. An email with a large attachment emits about 50gCO2e, and a spam message, not even opened by the recipient, is responsible for 0.3gCO2e.  The annual global footprint of spam is equivalent to 3.1 million passenger cars on the road using 7.6 billion litres of petrol  A web search on an energy-efficient laptop leaves a footprint of 0.2gCO2e, and on an old desktop computer some 4.5gCO2e A mobile phone SMS costs about 0.014gCO2e.


A plastic carrier bag leaves a footprint of 10gCO2e, and a paper bag 40gCO2e.


A pint (473ml) of water from the tap generates 0.14gCO2e compared to 160gCO2e for a 500ml store-bought bottle.   A large cappuccino comes at 235gCO2e, compared to 21gCO2e for a cup of black coffee or tea for which just enough water was boiled.


An hour of TV watching on a 38cm LCD screen yields 34gCO2e, compared to 88gCO2e on an 81cm LCD screen and 220gCO2e on a 61cm plasma screen.  1.6km of cycling powered by a meal of bananas would be responsible for 65gCO2e, compared to 260gCO2e for a mile powered by cheeseburgers.

  • Total global emissions in 2010 were estimated at 49 gigatonnes (Gt or billion tonnes) of CO2 equivalent (CO2e).
Sources: How Bad Are Bananas by Mike Berners-Lee; Fifth Assessment Report of the UN’s Intergovernmental Panel on Climate Change; McAfee’s Carbon Footprint of Spam study.