INTRODUCTION

Global warming and energy scarcity are threatening the human sustainability. Organisations must spend much effort in reducing the energy consumption and CO2 emissions. Buildings are one of the largest consumers of energy then they are also the largest contributor to the increase in the atmospheric CO2 and hence global warming and climate change. At the same time, building operation is likely to be especially affected by global warming. A rise in the ambient air-temperature can lead to a significant increase in electricity consumption and its associated CO2 emissions. Global warming is likely to increase the energy used for cooling residential buildings by 23.5% if the UAE warms by 5.9 ?. At the regional level, the energy consumption can be increased at around 5.4%. Consequently, the CO2 emissions can increase to almost 7.6 million metric tonnes. The net UAE CO2 emissions could increase at around 138.4 million metric tonnes over the next few decades.

To cope with global warming and the increase of CO2 emissions, two major changes in patterns are suggested in the UAE:

First, effective measures to protect the depleted resources and second, valid policies to replace fossil fuels with non-fossil. The former can be seen in the new building energy regulations. Implementing these regulations can reduce the CO2 emissions by 50%. The latter can be seen in establishing a new economic sector. This sector focuses on alternative energy and sustainable technologies through the installation of new power plants that use renewable resources in power generation. In addition, the construction of low energy and free carbon emission built environment such as Masdar City. Such a project can served as the foundation for an extension of activities in the field of low carbon emission buildings and renewable resources with the goal of reducing the impact of global warming on our life, economy and above all our built environment.

TWO IMPORTANT ISSUES HAVE BECOME A HOT TOPIC IN THE UAE-

1.The current energy situation that shows a trend of growing demand. In one decade (1997-2007), the primary energy of this region increased by 55.8% with 15.3% change between 2007 and 2008.

2.The increase of CO2 emissions. The statistics of the UAE show that the increase in CO2 emissions is within the range of 33% and 35% between 1997 and 2006. The Environment Agency of Abu Dhabi stated that the UAE activities in pursuing developments, such as fossil fuel combustion, industrial processing, land-use change and waste management have caused the release of greenhouse gas (GHG) emissions into the atmosphere. Consequently, temperatures in the UAE regions could significantly increase. This increase will influence the economy, built environment and above all the micro-climate of the UAE.

CURRENT AND FUTURE CLIMATE

The Environment Agency of Abu Dhabi and the Ministry of Energy studied different scenarios of climate changes and stated that temperatures in the UAE regions could increase while precipitation levels could significantly decline by the end of the 21st century. The annual average temperatures in 2050 are projected to be between about 1.6 ? and 2.9 ? warmer than they were over the period 1961 and between 2.3 ? and 5.9 ? warmer by 2100. It is clear that the climate of the UAE is tending to get warmer. This tendency is expected to impact the built environment, energy use in buildings and its associated CO2 emissions.

THE UAE STRATEGY TOWARDS SUSTAINABILITY IN THE BUILT ENVIRONMENT

Indeed, the less a country depends on finite resources such as natural gas and oil, the stronger and more stable the economy will remain in the face of energy cost increases or reduced supplies. From an environmental point of view, the expenditure of non-renewable energy has a direct impact on the natural environment. Thereby, following the example of developed world without any consideration to the local environment may lead to critical economic and environmental consequences. To avoid such consequences, two major changes in patterns are proposed, first, effective measures to protect the depleted resources and second, valid policies to replace fossil fuels with non-fossil fuels.

GLOBAL WARMING AND THE UAE BUILDINGS

The increasing emission of CO2 and its contribution to global warming has become a growing concern for building industry and regulation bodies in the UAE. There are 2 reasons-firstly, CO2 is the main by-product of the generation from fossil fuels of energy. As buildings are one of the largest consumers of energy then they are also the largest contributor to the increase in the atmospheric CO2 and hence global warming and climate change. Secondly, building operation is likely to be especially affected by global warming. Clearly, by using none renewable fossil fuels, buildings contribute to the CO2 emissions leading to warming the globe. In turns, global warming influences the energy consumption of buildings leading to increase the production of CO2 emissions.

ENERGY CONSUMPTION AND CO2 EMISSIONS

The rapid and increasing economic expenditure with huge architectural projects and population growth rates, makes  it one of the highest energy consumers per capita in the world. As the fraction of the total energy increases, the production of CO2 emitted becomes greater. It is important to note that the production and consumption of energy are the dominant source of GHG emissions in the UAE. The UAE statistic data show that about 4% of the CO2 production is caused by the direct emissions of buildings, 43% by electricity generation and 45% by manufacturing and construction [15]. The remaining is caused by other resources.

 IMPACT OF GLOBAL WARMING ON BUILDING DESIGN AND OPERATION

Due to the increase in air-temperature by 1.6 ? and 5.9 ? respectively,when this applies to the cooling and ventilation energy, a different scenario occurs. There is a sharp increase in the cooling energy which reaches a peak of 23.5% due to 5.9 ? increase. This increase represents a clear indication that global warming will lead to a negative impact on the total electricity demand, where changing from the current climate has reduced the heating energy demand at the expense of a rise in annual cooling energy demand, and therefore, additional total energy has been consumed. From the total energy increase there has been in effect a further CO2 increase, with electric cooling energy consumption.

POLICIES AND LEGISLATIONS TO REDUCE THE ENERGY DEMAND

There has recently been a consensus to legislate for energy efficiency in the UAE. The government has realised the benefits of energy efficiency not from the point of view of the balance between energy supply and demand, but rather from a socio-economic and environmental standpoint. As the building sector is a major consumer of energy, the UAE government has concentrated on this sector and recognised the important role that efficiency codes play in reducing the amount of energy consumption, especially that of the HVAC systems. The thermal insulation code was first applied. The green building codes  were then introduced. The new building energy codes conform to the most demanding global standards and have been developed in tandem with the International Code Council (ICC). An evaluation of the new building codes and their impact on energy and CO2 emissions showed that using such codes can reduce the CO2 emissions of buildings by 50%.

Source:

www.intechopen.com

www.footprintnetwork

www.bp.com

www.eia.doe.gov

www.masdar.ae