The Earth Day was observed on April 22. The first Earth Day was organised in 1970 with an aim to promote the thoughts of ecology, reverence for existence on earth and highlighting growing concern over pollution of the soil, air, and water.
The April 22 date was also designated as International Mother Earth Day by a resolution adopted by the United Nations in 2009. This is an annual day on which events are held worldwide to demonstrate and support for environmental protection. This year’s theme is: Trees for the Earth. This is because trees help to combat climate change. They absorb excess and harmful CO2 from our atmosphere. Scientists, climate experts, Governments and international organizations have all agreed that 350 parts per million (ppm) is the upper limit for CO2 in the atmosphere. Beyond 350 ppm, the planet can no longer support human life. In March, 2015, the global monthly average for CO2 concentration surpassed 400 (ppm). An obvious and necessary solution is to look for ways to dramatically cut carbon-emissions. But there are no longer sufficient trees on the planet even to absorb the amount of CO2.
In fact, in a single year, an acre of mature trees absorbs the same amount of CO2 produced by driving the average car 26,000 miles. Trees help us breathe clean air. Trees absorb odors and pollutant gases (nitrogen oxides, ammonia, sulfur dioxide and ozone) and filter particulates out of the air by trapping them on their leaves and bark. Trees help us to counteract the loss of species.
By planting the right trees, we can help to counteract the loss of species, as well as provide increased habitat connectivity between regional forest patches. Trees help communities achieve long-term economic and environmental sustainability and provide food, energy and income.
In majority of the urban areas throughout the world, the tree cover is declining and impervious cover is increasing due to the demand of the land for development. Urbanization appears to contribute to ever-growing levels of greenhouse gas (GHG) emissions and climate change.
The searing heat wave in western Odisha has reached a record temperature in April 2016. The daytime temperature in Titilagarh, known as the hottest place of the State, recorded 47 degree Celsius on April 22. Between 2006 and 2016, the maximum temperature in Titilagarh had never crossed 46 degree. This western Odisha town has been a hot zone for decades. However, the highest here was 48.1 degree recorded on April 30, 1999. As per Bhubaneswar Meteorological Centre sources, April 17 was one of the hottest days in the month of April as 20 towns recorded maximum temperature over 40 degree.
The very dense forest (VDF) and moderately dense forest (MDF) cover in Odisha has declined by 86 sq km, according to the latest report of India State of Forest Report (ISFR)-2013 compared to 2011. All lands with tree canopy density of 70 per cent and above are categorised as VDF while land with tree canopy density of 40 per cent and more but less than 70 per cent is taken as MDF. Degradation of forests is largely responsible for the change in climate over the land, variation in rainfall patterns and global warming.
Bhubaneswar was a city with pleasant climatic condition throughout the year. Since last decade Bhubaneswar is experiencing high population growth, urbanisation and distinct weather condition. The effects of climate change have been observed since last few years. It has been found to be excessive heat in summer. Over last one decade, the temperature of Bhubaneswar has been getting warmer and warmer by breaking the records in temperature rise and heat wave. The capital city created a weather history of 45.7 degree by breaking all time record in the month of April on temperature parameter. The city had recorded maximum temperature of 45 degree Celsius, highest so far in April, 1985. Average temperatures in Bhubaneswar have risen as tree coverage has declined and the number of heat-absorbing roads and buildings has increased. The number of rainy days has also been decreased in the city. Earlier, the city had a sound coverage of greenery but now it has decreased substantially, leading to uncomfortable conditions. Modification of the land surface by urban development and reduction of open space is another reason for the unusual mercurial rise in the city in summer. Small water bodies and wetlands are increasingly being filled up by multistoried buildings. The level of pollution has also increased due to increase in the number of traffic and decrease in green areas of the city. The expansion of the city and a lot of concrete structures are also the reason for microclimatic change over the years.
Human lives are largely supported by the benefits from trees. Trees cool the city, by shading our homes and streets and breaking up urban “heat islands” effect. In the warmer months of the year, urban areas realise lower ambient temperatures when trees are strategically planted along streets and near buildings. Footpaths, which are provided at the sides for pedestrians, have to be shaded by rows of trees. The open spaces of a city perform a variety of functions and a variety of uses. By this, cities can maintain green space within and throughout their urban and suburban centres, including trees and green space for recreation, cooling, storm water management and simple aesthetic enhancement and livability. a coherent
City “climate action plans” often incorporate urban forestry into climate change mitigation and adaption strategies. An active urban forest management for climate change strengthens community resilience to climate change impacts. Urban forests should be included in the city planning process. Forest edges are therefore to be regarded as essential and permanent protection and should never be cut or removed.
(Dr Praharaj works in the Department of Architecture, College of Engineering and Technology, Bhubaneswar)