Unity on climate change has never been more urgent

Learning from the devastation in the Philippines

The rising death toll from Typhoon Bopha which hit Mindanao in the Southern Philippines this week highlights the vulnerability of communities around the world to the impact of climate change and serves as a timely reminder to government representatives currently at the UN Climate Change Conference in Doha of the need for urgent collective action.

I witnessed myself the devastation that such violent storms can cause during my visit with UNICEF UK to Mindanao just a year ago in the aftermath of Typhoon Washi which killed thousands of people. Seeing the devastated area and talking with the government, NGOs and survivors in the refugee shelters it was clear that despite the tragedy reconstruction was already underway. During my visit I was told that typhoons and tropical storms were less common in the south of the country but climate change means that more areas are becoming increasingly vulnerable. I can’t help but think about the people I met who had lost everything and were trying to rebuild their lives. As a result of climate change those same people may now be facing situations such as this with increasing regularity. 

It is the most vulnerable in society who are likely to be the ones who will be the most affected by these events. UNICEF estimates that there are approximately 756 million children living in the ten countries most vulnerable to climate change and at least half of all people who die in disasters are children. They experience unimaginable fear and confusion as they attempt to deal with the loss of the most stable aspects of their lives, whether that is family members, their home, regular meals or schooling.

The Philippines is listed as the sixth country in the world most vulnerable to climate change and the response to Typhoon Bopha has been a good example of how preparatory measures can save lives. The people in affected areas had been warned by phone messages, the media and the government. It is vital to ensure the most vulnerable, including children, are adequately prepared and the new global institution for finance, the Green Climate Fund, should be constructed in a way that ensures it helps to deliver protection for children in the most vulnerable countries.

As international leaders meet this week at the 18th Conference of the Parties of the United Nations Framework Convention on Climate Change (COP18) ambitious action is needed to ensure global emissions are reduced. We cannot afford not to recognise the impact of climate change on the lives and wellbeing of those in developed and developing nations alike. Governments must also ensure that they mobilise new and additional funds for 2013 and beyond to meet the global goal of $100bn a year by 2020. It is essential that the resources are available for the adaptation measures needed to ensure that children in all nations do not grow up in a world of further climate extremes. I hope that COP18 will put the needs of children at the heart of initiatives to limit the damage of climate change.

As people in the UK battle to save their homes from floods, families in America seek to repair the damage wrought by Hurricane Sandy and this latest typhoon claims further lives in the Philippines the importance of our commitment to address climate change has never been clearer. It has confirmed to me once again how we are united in our differences. The capacity of people to weather the storm must be equal no matter on what continent the storm lands and the current UN negotiations provide an important opportunity to demonstrate a united response to the global problem of climate change.

Tony Cunningham is Shadow International Development Minister, MP for Workington

Damage wrought by Typhoon Bopha in the Philippines (Getty Images)
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Inside Big Ben: why the world’s most famous clock will soon lose its bong

Every now and then, even the most famous of clocks need a bit of care.

London is soon going to lose one of its most familiar sounds when the world-famous Big Ben falls silent for repairs. The “bonging” chimes that have marked the passing of time for Londoners since 1859 will fall silent for months beginning in 2017 as part of a three-year £29m conservation project.

Of course, “Big Ben” is the nickname of the Great Bell and the bell itself is not in bad shape – even though it does have a huge crack in it.

The bell weighs nearly 14 tonnes and it cracked in 1859 when it was first bonged with a hammer that was way too heavy.

The crack was never repaired. Instead the bell was rotated one eighth of a turn and a lighter (200kg) hammer was installed. The cracked bell has a characteristic sound which we have all grown to love.

Big Ben strikes. UK Parliament.

Instead, it is the Elizabeth Tower (1859) and the clock mechanism (1854), designed by Denison and Airy, that need attention.

Any building or machine needs regular maintenance – we paint our doors and windows when they need it and we repair or replace our cars quite routinely. It is convenient to choose a day when we’re out of the house to paint the doors, or when we don’t need the car to repair the brakes. But a clock just doesn’t stop – especially not a clock as iconic as the Great Clock at the Palace of Westminster.

Repairs to the tower are long overdue. There is corrosion damage to the cast iron roof and to the belfry structure which keeps the bells in place. There is water damage to the masonry and condensation problems will be addressed, too. There are plumbing and electrical works to be done for a lift to be installed in one of the ventilation shafts, toilet facilities and the fitting of low-energy lighting.

Marvel of engineering

The clock mechanism itself is remarkable. In its 162-year history it has only had one major breakdown. In 1976 the speed regulator for the chimes broke and the mechanism sped up to destruction. The resulting damage took months to repair.

The weights that drive the clock are, like the bells and hammers, unimaginably huge. The “drive train” that keeps the pendulum swinging and that turns the hands is driven by a weight of about 100kg. Two other weights that ring the bells are each over a tonne. If any of these weights falls out of control (as in the 1976 incident), they could do a lot of damage.

The pendulum suspension spring is especially critical because it holds up the huge pendulum bob which weighs 321kg. The swinging pendulum releases the “escapement” every two seconds which then turns the hands on the clock’s four faces. If you look very closely, you will see that the minute hand doesn’t move smoothly but it sits still most of the time, only moving on each tick by 1.5cm.

The pendulum swings back and forth 21,600 times a day. That’s nearly 8m times a year, bending the pendulum spring. Like any metal, it has the potential to suffer from fatigue. The pendulum needs to be lifted out of the clock so that the spring can be closely inspected.

The clock derives its remarkable accuracy in part from the temperature compensation which is built into the construction of the pendulum. This was yet another of John Harrison’s genius ideas (you probably know him from longitude fame). He came up with the solution of using metals of differing temperature expansion coefficient so that the pendulum doesn’t change in length as the temperature changes with the seasons.

In the Westminster clock, the pendulum shaft is made of concentric tubes of steel and zinc. A similar construction is described for the clock in Trinity College Cambridge and near perfect temperature compensation can be achieved. But zinc is a ductile metal and the tube deforms with time under the heavy load of the 321kg pendulum bob. This “creeping” will cause the temperature compensation to jam up and become less effective.

So stopping the clock will also be a good opportunity to dismantle the pendulum completely and to check that the zinc tube is sliding freely. This in itself is a few days' work.

What makes it tick

But the truly clever bit of this clock is the escapement. All clocks have one - it’s what makes the clock tick, quite literally. Denison developed his new gravity escapement especially for the Westminster clock. It decouples the driving force of the falling weight from the periodic force that maintains the motion of the pendulum. To this day, the best tower clocks in England use the gravity escapement leading to remarkable accuracy – better even than that of your quartz crystal wrist watch.

In Denison’s gravity escapement, the “tick” is the impact of the “legs” of the escapement colliding with hardened steel seats. Each collision causes microscopic damage which, accumulated over millions of collisions per year, causes wear and tear affecting the accuracy of the clock. It is impossible to inspect the escapement without stopping the clock. Part of the maintenance proposed during this stoppage is a thorough overhaul of the escapement and the other workings of the clock.

The Westminster clock is a remarkable icon for London and for England. For more than 150 years it has reminded us of each hour, tirelessly. That’s what I love about clocks – they seem to carry on without a fuss. But every now and then even the most famous of clocks need a bit of care. After this period of pampering, “Big Ben” ought to be set for another 100 or so years of trouble-free running.

The Conversation

Hugh Hunt is a Reader in Engineering Dynamics and Vibration at the University of Cambridge.

This article was originally published on The Conversation. Read the original article.