I want to tell you the story of this post. Some weeks ago I was working on this post and I was mulling over about what to write. I am interested in sustainability and in climate change and I was keen to write a post about this last topic. A general post, just an introduction to a series of future posts that will be more focused on these two themes. Some days ago my post was ready to be published on this blog. A general post on climate change: global and local warming; the social and economic consequences and the potentials in finding incentives to fight the battle against emissions. The same night, surfing the internet and reading news, I bumped into a very inspiring video in which Al Gore talks about the same topics. Agrrrrrr…post to be trashed! Auchhhh…no! But…not, wait! You know what?!? I will not trash this post. Me and Al Gore talking about the same topics. This is absolutely thrilling! And surely, up to date, it is the highest point of my career!!!! Let’s duet! Enjoy the reading and the video.
In the last decades we are assisting to the increase in global temperature and in the number of extreme events. A recent study conducted by Dr. James Hansen and colleagues shows that 2014 is the warmest year of the last decades. The global surface temperature in 2014 was the highest since instrumental data are recorded. However, more important, Hansen and colleagues predict that in the next years we will assist to more warming.
Global and local temperatures are rising and, the consequences are well-known to everybody. We have to admit, global and urban warming are NOT cool! However, there is no one else to blame except ourselves, since, as the IPCC’s 5th Assessment Report states, climate change is mainly of anthropogenic origin. Change in land use, deforestation, and release of well mixed greenhouse gases, to name a few, are among the most important causes of climate change.
The increase in the global temperature affects biodiversity and provokes extreme climate events such as hurricanes and droughts. Cities, where most of the human population lives, are experiencing the worst consequences of climate change. Heat waves, floods – especially in coastal areas – and heavy downpours are amongst the climate hazards cities are facing. Furthermore, the use of impervious and dark materials, the decrease in natural vegetation, the canyon effect, the emissions related to heating – to name a few – contribute to a further local energy imbalance: a warming phenomenon called urban heat island.
The effects of urban warming and of the increase in global temperature are additive. Most of the people experiencing the consequences of the raise in temperature are socially and physically vulnerable: elderly, people with physical diseases and people who cannot afford air conditioning systems. In other cases, the victims of such extreme climate events already live deprived of sanitation, such as in developing countries. In this way, climate change exacerbates poverty and social inequity.
Together with the severe social consequences, also economic effects arise. In 2005 the hurricane Katrina provoked damages of about $40-50 billion and 1500 deaths in Louisiana . In 2012 hurricane Sandy hit New York City causing damages of about $50 billion. In 2003 Paris experienced a heat wave that provoked a severe increase in the urban population deaths.
The battle against climate change is mainly played on two fields: mitigation and adaptation. Although climate change is a topic policy makers should be concerned about at different scales, it seems that international negotiations and in local/urban policies are two conflicting dimensions. In many cases, local authorities are reluctant to accept top-down mitigation plans. In contrast, bottom up mitigation and adaptation strategies are well accepted when they can provide benefits for citizens, for instance in terms of human health enhancement and cost savings.
Just some years ago in the United States, Mayor Michael Bloomberg started carrying forward an urban plan for New York City with the aim to convert black flat roofs into white ones for reducing summer temperatures. Besides, Portland invested more in the substitution of commonly used black roofs with green ones, able to reduce rain runoff, to provide better thermal insulation for buildings and to contribute to the mitigation of the urban heat island effect. To incentivize the conversion of black roofs into green ones, the city offers a bonus for floor-area-ratio to citizens who install green roofs.
The examples provided clearly show that although a discrepancy between different scales of policy making are visible, the interest towards promoting better local living conditions or a better local economy also shows that a leeway for negotiations exists.
Now I leave the stage to Al Gore. Al, it is your turn!