The GAS NATURAL FENOSA Foundation presented ‘La calidad del aire en las ciudades. Un reto mundial’ yesterday, a publication that analyses the causes and consequences of poor air quality and suggests improvement plans and ways to deal with the problem.
This publication, promoted by the power company’s foundation, has been coordinated by Xavier Querol, a research professor at the National Scientific Research Council (CSIC), and received contributions from 18 leading experts worldwide.
The book’s aim is to highlight how “air quality is just as important a problem as climate change but with more immediate adverse effects, and the solution requires us all to work together”, explained Martí Solà, General Manager of the foundation.
It presents air quality in a practical way through the experiences of various cities around the world, such as Madrid, Barcelona, Berlin, Mexico, Santiago de Chile, Bogota and the Lombardy region in Italy. It analyses the level of harmful particulates present in the atmosphere, as well as the climate and health problems they can cause.
The impact of road transport
In the last 50 years, energy consumption per capita around the world has risen by 60%. This has led to a 65% increase in CO2 emissions. To a great extent, such a large increase is due to the growing number of motor vehicles on our roads. In that regard, transport accounts for approximately one-third of energy consumption in the Member States of the European Union and over one fifth of greenhouse gas emissions.
At present, only one in ten people live in a city that meets the guideline air quality parameters of the World Health Organisation (WHO). These WHO guidelines are more restrictive than European legislation, which has thresholds and targets that were set in the late 1990s and have not been changed since. There is therefore a clear need to adjust these figures to the WHO guidelines, especially in regard to the pollutants with the greatest impact on mortality, such as particulates (PM2.5 and PM10).
Besides these pollutants, which cause almost 400,000 deaths a year in Europe according to the European Environment Agency, ‘La calidad del aire en las ciudades’ also examines others such as sulphur dioxide (SO2), nitrogen dioxide and nitrous oxides (NO2, NOx), lead (Pb), benzene (C6H6), carbon monoxide (CO), arsenic (As), cadmium (Cd), nickel (Ni), Benzo[a]pyrene (B(a)P) and ozone (O3).
Natural gas as an ally. The cases of Madrid and Barcelona
In this field, natural gas vehicles (NGV) have a decisive role to play in improving air quality, specifically regarding the concentrations of NO2 and particulate matter (PM10 and PM2.5) in large cities. This is one of the conclusions reached from the experiences in Madrid and Barcelona by José María Baldasano, professor of environmental engineering at Universidad Politécnica de Cataluña and member of the Barcelona Supercomputing Center, which analyses various scenarios based on replacing a percentage of the current number of vehicles with others powered by natural gas.
The scenario producing the greatest change in emissions is the Escenario Suma (ES), which implies a reduction in the emissions of O3 (NOx, COVs) precursors and other pollutants (CO, SO2, NH3, PM10, PM2.5) for the Barcelona area of 38 t/day (13,800 t/year) and for the Madrid area of 99 t/day (35,800 t/year). In total, almost 50,000 fewer tonnes of emissions resulting from a replacement of 11.2% of vehicles in Barcelona and 13.4% in Madrid with natural gas vehicles.
The most effective individual measures analysed for improving air quality both in Madrid and in Barcelona are the conversion of 50% of goods delivery vehicles (Scenario 4 – E4) and 10% of private cars (E5).
The replacement of buses and heavy vehicles for goods transport is less relevant (they account for less than 0.25% of the total number of vehicles), although such action would considerably reduce the emissions of SO2 and particulates (PM10 and PM2.5) owing to the large impact of heavy diesel vehicles on the emissions of these pollutants.
The conversion to natural gas of certain diesel or petrol vehicle fleets is being presented as a feasible option for reducing the concentrations of NO2 and especially particulate matter (PM10 and PM2.5) in such major cities as Barcelona or Madrid, which implies an air quality improvement.
