Climate Disruption: New Delhi's Trees Need A Helping Hand

There are over 250 species of trees spread liberally throughout 579 square miles of metropolitan New Delhi and its breathtaking Delhi ridge or Lungs of Delhi. Soon the total number of trees will be revealed from a 2012 census. The magnificent hundred year old plus neems, vilaiti keekars, amaltas, jamuns, semuls, siris, ashoks, gulmohars and many others make the city attractive and more livable.

As the monsoons begin to retreat over the next few days, crucial rains have sufficiently watered the older city trees. New Delhi loves its trees. So when the United Nations Habitat recently ranked the city 58th out of 95 cities in the State of the World's Cities Green Index, the New Delhi Municipal Council passed measures to safeguard the city and its trees.

Urban trees are vitally important for so many reasons. As climate change hastens with more extreme weather, and make no mistake, there's ample evidence to suggest it will. For instance, when monsoons are late or fail to arrive, severe widespread droughts occur, and there have been three droughts since 2000 including the devastating event of 2009. That year India had to import sugar, pushing global prices to 30-year highs. The 2009 drought significantly impacted Assam's tea as production dropped to a low of 442,000 metric tons. Temperatures have risen in that region by 3.6 degrees Fahrenheit during the last 80 years. Now fewer sunshine days during the monsoonal season have increased the number of damp days. In turn, this has created favorable conditions for the tea mosquito bug, which attacks fresh shoots of the tea bush. Last week, researchers at the Potsdam Institute for Climate Impact Research predicted that the Indian monsoon would fail more often in the coming decade(s) as greenhouse gas emissions continue to rise, unchecked.

New Delhi must plant more trees. And it's not just planting sapling to replace the old trees; it's a matter of each homeowner and shopkeeper taking on the responsibility to tend the young trees and maintain the old ones. Droughts kill trees. Residences and businesses of New Delhi will need to regularly water city trees in the coming decade(s). Water could easily be harvested from rooftops of homes and (or) nearby buildings and stored in large tanks until trees require it.

Trees are crucial for all cities and towns, globally. Let me tell you why:

Every tree in the world participates in many biological processes, but the one of the most notable is photosynthesis. In this process, tree leaves absorb CO2 from the atmosphere, mix it with water, convert it into sugar using the sun's energy, and give off oxygen as a by-product. Carbon is stored in the wood during the process. In fact, trees are effectively the greatest CO2 warehouses to have ever evolved on Earth. For every metric ton of wood created, 1.5 metric tons of CO2 is absorbed and 1 metric ton of oxygen is released.

Today, economists and biologists are reuniting for a sustainable future in the face of climate change and a burgeoning population. In fact, scientists are able to place a dollar value on the importance of healthy trees and the services they provide New Delhi. It's called 'Ecosystem Services' and New Delhi's urban trees are worth $3 billion (US), annually.

New Delhi's trees save the city council tens of millions of dollars in storm water runoff protection. Trees catch the rainfall and billions of roots absorb water and regulate its flow to sewers. Mature trees placed strategically around homes, schools, hospitals and factories can reduce cooling costs by 40 percent.

Moreover, New Delhi's mature trees improve air quality by filtering city air: Lungs of Delhi and parks absorb 85 percent of air pollution and city trees by as much as 70 percent. Trees also provide an excellent noise buffer and habitat for urban animals including honeybees. Did you realize that one mature tree produces enough oxygen in a year for a family of four!

Sadly, many older New Delhi trees are reaching the end of their life span. And many mature trees are suffering from choking; that is, concrete closer than 6 X 6 feet from the trunk. In fact, Delhi's forest department has instructed three municipal corporations, public works and the central public works departments to expedite removing concrete around trees throughout the city. The Capital's tree authority is committed to planting tens of thousands of trees, protecting its citizens from the onslaught of extreme weather.

Climate change is a citizen's issue; each of us is required to lend a helping hand. That means taking ownership of our urban trees including watering them during the drier summers, forthcoming.

Earth Dr Reese Halter is a broadcaster, biologist, educator and author of The Insatiable Bark Beetle and The Incomparable Honeybee