If the question is whether trees and vegetation serve to combat the heat, the Bioparc of Valencia has the answer: 13 degrees less

Going out for a walk through the center of a big city at three in the afternoon in the middle of July is a great challenge for many people because they literally begin to roast due to the high temperatures. But in these situations, taking shelter in a dense park promises relief almost immediately, as has been demonstrated in different areas of Valencia such as the Bioparc, where the wind chill drops 13 degrees with respect to the asphalt environment, as its sensors have demonstrated. A question of perception. When we read “13 degrees minus”, our brain immediately thinks about the air temperature. And this is where it is important to qualify, since a tree is not going to take air at 40 °C and magically convert it into air at 27 °C. However, air temperature is only part of the equation. What really determines whether we are comfortable or on the verge of heat stroke is the cthermal comfort, measured by indices like PET (Physiological Equivalent Temperature). These indices take into account air temperature, but also humidity, wind speed and, above all, the average radiant temperature. On the street. Science in this case shows that direct solar radiation on our skin and the heat radiated by hot asphalt trigger our thermal stress. A specific study on shade infrastructure and outdoor thermal comfort demonstrated that urban shading can reduce the PET index between 9.4 and 17.1 ºC. Therefore, the 13-degree drop cited by the Valencia data fits perfectly with what science has been measuring for years. The air temperature does not drop drastically, but the radiant load does plummet. Why are trees so good? Here science has shown that tree canopies block direct solar radiation, and a field study of tree shading confirms that this interception of sunlight causes large drops in the mean radiant temperature under the canopy, eliminating the “oven effect” of direct sun. But they also act as a natural air conditioner, since, unlike a metal awning or pergola, which heat up and radiate heat, the trees are alive. This means that they absorb water through the roots and release it in the form of vapor through the leaves. This process consumes thermal energy from the environment, actively cooling the air around them, even if it is a few tenths or a couple of degrees. We need trees. The debate about whether to put more or fewer trees in a square is no longer a purely aesthetic or landscaping issue. It is directly a matter of public health, since science is quite clear that exposure to extreme heat triggers mortality and morbidity. That is why these natural environments act as a protective shield that is very necessary. It is no coincidence that institutions such as the Climate Cities Network are publishing technical guides to integrate “climate shelters” into urban planning. And it is no wonder because a climate shelter is nothing more than a space that offers safe thermal conditions for the vulnerable population during episodes of extreme heat. And the data makes it clear, since a well-designed park, with trees with wide, dense crowns, is one of the best possible refuges. Images | Andy Lee In Xataka | In the 19th century it was planted in parks for its beauty: today this tree is one of the trees that breaks the most pipes and sidewalks in Spain

vegetation is migrating northwest

If we look at the Earth from space, in addition to distinguishing the shapes of the continents, great milestones of nature and some other human construction such as the greenhouses of Almeríawe can also observe how time and the seasons pass: the terrestrial vegetation follows a seasonal pattern, a kind of green wave that runs across the surface of the planet from north to south. Thus, in the boreal summer, the maximum of greenery moves towards the north. In the southern summer, towards the south. From space we can also observe climate change and its effects. Without going any further, the peninsula it cracked after from the torrent of rain at the beginning of the year and that green belt is also moving. Specifically, 14 kilometers a year, according to has determined a research team from the University of Leipzig, the German Center for Integrative Biodiversity Research and the University of Valencia. The discovery. The green wave is moving northwest and it does it faster and faster. The southern hemisphere takes the cake: between 2010 and 2020, displacement accelerated to 14 kilometers per year. Furthermore, it does so in a way that the scientific community did not expect: the center of global vegetation is moving north in both hemispheres. That it would do so in the northern hemisphere was expected, but that it would do so in the south was not (based on the patterns, one would expect it to move south). But it is also moving towards the east, breaking all schemes. Why is it important. It is the first global metric of biological cycles expressed in kilometers, a magnitude as clear and intuitive as sea level or temperature and that works as if it were a compass. What this indicator says is that the north and south amplitude of the green wave is reducing: if you put a point on the map representing where the center of gravity of all the vegetation on the planet is, it would be moving towards the northwest. The planet “greens” in an increasingly asymmetrical way. They explain that in a high emissions scenario, the eastern shift will end up dominating over the north at the end of the century. This involves a profound reconfiguration of where and when the Earth’s biosphere functions, which will affect carbon cycles, migrations and ecosystems. Context. Global warming takes spleen the arm the global greeninga widespread increase in vegetation documented since the 1980s and concentrated especially in the northern hemisphere. The reason is global warming (as winters are shorter, plants have more time to grow), carbon dioxide that acts as fertilizer and that countries like China and India have intensified their agriculture. In fact, they are the drivers of change. Why east? It is a direct consequence of the above: in short, because East Asia, India, Europe are “pulling” the center of gravity of global greenery towards the east. And South America does just the opposite: the vegetation there is losing strength, due to causes such as deforestation, droughts or changes in land use. Not only has East Asia become greener in recent decades, we know it now drags the center of gravity of the entire Earth’s biosphere. How have they done it. To arrive at this metric and its effects, they have taken satellite data from 1982 to 2020 and have validated the results with six models of the Earth system of the CMIP6 projectwhich coordinates the simulations of the most advanced climate models. From here, the research team has calculated the center of mass of all terrestrial vegetation in 3D Cartesian coordinates (called a centroid), weighted by greenness indices. They have called the moment of maximum hemispheric greenness viridistice, like the solstice. The resulting trajectory summarizes the dynamics of biological cycles in a single curve. In Xataka | Spain today has 12 more days of “extreme risk” of fires per year: the cause is neither arsonists nor ranchers In Xataka | A plant from the Red Sea has appeared in the bay of Palma. It is a bad omen for the future of the Mediterranean Cover | Harsh Kumar

Log In

Forgot password?

Forgot password?

Enter your account data and we will send you a link to reset your password.

Your password reset link appears to be invalid or expired.

Log in

Privacy Policy

Add to Collection

No Collections

Here you'll find all collections you've created before.