menu horizontal
Botón que abre el buscador
Calendar
Lecture Series

20, 22, 27, 29 November, and 4 December 2007
Image of the Lecture

The participants summarise their talks

  • The human influence on the coming climate
    Joan Grimalt

    Science and technology are without doubt a benefit for all countries. As a matter of fact, they have transformed the human history and the planet itself. And this has occurred rather recently. Humans have inhabited planet Earth for several millions of years. In the past we discovered two activities that have allowed us to transcend our condition of simple ecosystem components: namely, making fire and agriculture. Nevertheless, the most vital invention is much more recent. Around 200 years ago we learned how to obtain work out of heat. This was really the key step  because it freed a lot people from having to depend from manual works. This is the discovery that triggered the industrial revolution.

    Having a higher percentage of people devoted to thinking changed the world. In these last 200 years the scientific basis of physics, chemistry and biology were set. From the technological perspective we have the inventions of the steam motor and explosion motors, the development of nuclear energy, and the beginning of space exploration. From the sanitary perspectives, we have obtained vaccines, antibiotics, and surgery has reach a great development. As a consequence of all, we have seen how the average life expectancy has gone from around 40 years, up to an interval around 75-80 years.

    All of this has also caused a huge increase of the world population. The average number of humans used to be around 50 millions. The increase was very slight until we reached the industrial revolution that gave way to reaching the 6300 millions of humans we have now. This is a completely novel and unique historical situation, and poses a number of threats that we will have to overcome.

    The huge consumption of fossil fuels has produced an important increase in atmospheric CO2. Any kind of combustion produces CO2 in the best possible scenario (in the worst, a mixture of diverse contaminants). Along the last 150 years the concentration of this gas has increased around 100 parts per million due to human activities. This increase is equivalent to what has happened naturally each time our planet has gone from a glacial period to an interglacial period. But on top of this, the current concentration of CO2 (380 parts per million) is still higher that in any concentration observed in interglacial (280 parts per million) or glacial (190 parts per million) period of the Quaternary. The current situation of the planet is totally unexpected from the point of view natural evolution. There is no equivalence of such high CO2 concentrations in the atmosphere in any recent past.

    The CO2 is a gas that causes the greenhouse effect by generating a "thermal blanket" in the atmosphere. The higher the concentration of gas, the higher the temperature. The current data show with a 95% of certainty that the average temperature of the current years is superior to the observations along the last 2000 years. As a consequence of this increase (of about 0.6ºC in the present), there is a generalized melting of ice that can be particularly observed in mountain tops, but also in the North and South Poles. Also, the sea level has increased around 25-30 cm along the 20th century. But we are still at the beginning of this process. 

  • Climate change influence on terrestrial life (Iberian examples)
    Josep Peñuelas
    In Spain there are already a significant amount of observational evidences of the biological effects of climate change. The biological spring has been moved forward and the arrival of winter has been delayed, making the vegetative period 5 days longer every decade along the last fifty years, and in the mountains Mediterranean vegetation seems to be moving to higher altitudes. Many other modifications due to climate change have been observed along the last decade: more frequent and severe droughts, increased fire risks, higher emissions of biogenic volatile organic compounds of our ecosystems, etc. If the warming and the decrease of the precipitations foreseen for the next decades finally happen, they will affect the physiology, phenology, growth, reproduction, establishment and, finally, the distribution of living beings, and thus, the structure and functioning of the ecosystems. As a matter of fact, it has already been tested in experimental studies simulating warming and drought that some species will be more affected than others, causing the alteration of their competitive ability, which ultimately produces a modification in the composition of the communities. It has been observed for example that there is a decrease of diversity in our forests and bushes. Together with the structural changes, these studies have observed functional changes, like for example the decrease in CO2 absorption due to droughts, or the loss of nutrients in the leached after rains in response to global warming. Also, it has also been tested how the organisms will attempt to adapt even genetically to the new conditions, but this happens at a slower pace than climate change. The changes affect, and will affect, multiple productive, environmental and social services provided by terrestrial ecosystems. For example, the role of many of our terrestrial ecosystems as carbon sinks will be deeply compromised along the following decades. In the next years, the "a-forestation" policies of the abandoned agricultural spaces and the "reforestation" of disturbed zones should take into consideration the conditions that are projected for the near future.
  • The impact of climate change on the Spanish coast
    Íñigo Losada

    The coastal areas are highly dynamic and present a great variability along relatively short time periods, which produce a great fragility and vulnerability against any kind of external pressure, whether it is of natural or human origin. In this context, the impact of climate change over them can have consequences of great relevance, and in many occasions, irreversible. In the conference we will address the main impacts that climate change can have over the coastal areas, focusing on the physical aspects and the possible consequences over the biotic and social-economic environment.

    We will review the effects that climate change can have over the agents "modeling" our coasts, showing trends that have been observed in our coasts along the last decades and extrapolating them to the horizon of year 2050. From there we will show the detailed results of the expected impacts in our coasts. Finally, we will address the different adaptation strategies needed to face these impacts.

  • Climate in the Mediterranean basin: atmosphere-sea-land interactions
    Millán Millán

    Along the last 20 years, the results of several European projects have shown the loss of summer storms along the Mediterranean basin. Also, important differences have been detected between measurement stations of the interior and the coast, because while the yearly average precipitation in the coastline has not really changed, we have observed in the interior stations how it tends to decrease. Another significant data are the increase of torrential rains in general, and particularly in spring (when torrential events are higher).

    Upon the perspective of this negative change in the precipitation regime, and according to the results of our research, we can confirm that the decrease of vegetation on the slopes of our mountains and the drying of wetlands in our coasts are contributing significantly to these climatic change processes. Synthetically, the humidity that arrives with the Mediterranean breezes needs an additional contribution of water vapor coming from the terrestrial surface to result in storms before being incorporated into the general circulation. If this contribution is insufficient, the storms will not trigger and the water vapor returns creating strata up to 5500 m above the Mediterranean Sea. In this case, our litoral mountains behave like orographic chimneys that connect the winds in surface with their return in altitude. These kind of accumulation cycles normally last 3 to 10 days in summer, and during these cycles, water vapor enhances the greenhouse effect of other contaminants as this is 47 times more effective than CO2 (E.g., ozone x 200); with all of this, the surface of the sea overheats as much as the terrestrial surface due to the loss of storms.

    All these processes alter the historical climatic equilibrium in the western Mediterranean basin and changes it into a new dryer state. But on top of this, these local perturbations in the cycle can propagate to other regions along the rest of the basin, and this way, the accumulated water vapor migrates towards the east of Europe provoking the floods that have been registered in summer in Romania, Austria, etc. But the most important fact is that with these changes in the Mediterranean,  also the Atlantic current of salt water is altered and increases, affecting this way the transition of the frontal Atlantic systems that no longer go into the peninsula (we loose storms, drought increases) and move north causing more intense rains in Ireland and Great Britain during the autumn. This means that the perturbations are transported to regions other than the Mediterranean basin.

  • Energy and environment, intertwined problems
    Pedro Gómez Romero

    Our preferred species, that which call itself intelligent, has been inhabiting the planet for tens of thousands of generations. But it has only been eight generations, after someone Watt perfected the machine designed by Newcomen, since the Homo sapiens learned how to use the energy of the sun, condensed in the shape of fossil fuel to feed a social metabolism that has not ceased to grow since then. Our irrational and excessive energy consumption and our addiction to fossil fuels (which represent 85% of the energy we consume) are leading us to a slow but irremediable unprecedented double crisis cause by the intertwined problems of energy and environment.

    This conference will analyze the interrelation of the energy consumption and the environmental problems, and, due to the lack of magical solutions, will review some of the actions that should be started and the possible alternatives to our energetic model.

Fundación Juan March
Contact
Castelló, 77 – 28006 MADRID – Spain
+34 91 435 42 40 – Fax: +34 91 576 34 20
http://www.march.es