Renewable energies and green cities: what are the actions that could stop climate change

An ultimatum. This is how the latest report issued by the Intergovernmental Panel on Climate Change (IPCC), which reports to the United Nations (UN), could be described, which stated: “It is now or never.” Time is running out and the planet is already registering an increase of 1.1°C. The established limit was between 1.5°C and 2°C by the end of the century. If these figures were exceeded, the outcome would be irremediable: climate catastrophe. However, there are some actions that scientists highlighted as positive, since a group of researchers stated that these goals are achievable. Can global warming be stopped?

Greenhouse gas emissions driven by the burning of fossil fuels generated an acceleration in the rise in the planet's temperature, experts said. In the Paris Agreement, some 200 countries agreed, albeit in a non-binding way, the limit of between 1.5°C and 2°C. However, the more than 265 scientists, belonging to 65 countries, who analyzed the world situation, assured that mitigation measures must be applied and zero emissions should be applied to stop the climate catastrophe. In short, if emissions do not touch its ceiling and do not start to fall in 2025, that is in 3 years, this hard outcome is almost guaranteed.

Although the future seems bleak, there are still some positive points. According to the IPCC report, the goal can still be achieved but it depends on the commitment of nations. However, the fall in the cost of implementing and generating renewable energies and a green future for cities would allow this goal to be achieved. In that tone, a recent study published in the journal Nature assured that these goals can be achieved, although they put a big question mark on the implementation of the pledges that countries made in 2015.

Renewable energies gain ground in the world

Beyond these arguments, the truth is that the document released a few days ago left some positive points, such as the fall in the costs of renewable energies and the possibility of actions being carried out in cities that make them greener. This could lead to a decrease in the generation of carbon dioxide, which is mainly responsible for this situation.

According to experts, between 2010 and 2019 there was an 85% drop in solar energy generation prices. Meanwhile, wind power fell by 55%, while the production of lithium batteries showed a shrinkage of 85%.

But that's not all, between 2015 and 2019 the world managed to increase its wind power generation, which increased by 70%. In parallel, solar photovoltaic energy production grew by a staggering 170%. With this data, the experts pointed out that, in 2019, so-called clean energy was responsible for procuring 37% of the world's electricity.

“Climate change will not have a substantial impact on future wind resources and will not compromise the ability of wind energy to support low-carbon transitions,” the document said, while warning that “there is limited evidence that extreme wind speeds, which can damage turbines. wind power, will increase due to climate change”.

In that regard, focusing on solar power generation, IPCC experts noted: “Climate change is not expected to substantially affect global solar 'insolation' and compromise the ability of solar energy to support low-carbon transitions.” “Future photovoltaic technologies are likely to be more efficient,” the document said, stating that “cloud cover is expected to decrease in the subtropics (around -0.05% per year), including parts of North America, large parts of Europe and China, South America, South America, South Africa and Australia,” continues the written.

He concluded that “the models project modest increases (< 3%) in solar photovoltaic energy by the end of the century in southern Europe, northern and southern Africa, Central America and the Caribbean”. “Demand for heating will decrease and demand for cooling will increase in response to climate change,” experts predicted, warning that “transmission and storage needs” may be affected, as well as “demand-side management and maximum generation capacity.”

Green cities: an urban response to climate change

Cities are home to both people, industries, factories and transport. With this in mind, IPCC experts pointed out the importance of transforming large cities with greener and more sustainable spaces. At present, according to the World Health Organization (WHO), 99% of the world's population breathes poor quality air, resulting in more than 13 million deaths per year from preventable environmental causes.

According to some scientific estimates, by the end of the century, 85% of the world's population will live in large cities. Some will even inhabit the so-called “megacities”. However, these towns are currently invaded by cement, iron and concrete, materials that do not absorb carbon dioxide, as do trees and green spaces. Even most of the energy consumed is based on fossil fuels (oil, gas and coal).

Since 1990, according to the IPCC report, urban buildings have increased their greenhouse gas emissions by 50%. Hand in hand with renewable energies, experts warn that these large cities could reduce their generation to a figure close to zero. The methodology would be to green these cities with a dual objective, that they capture CO2 and, in addition, do not expel emissions.

According to some estimates, this goal is widely achievable, since 60% of the buildings that will be part of the 2050 urban scene have not yet been built. It is for this reason that they warned the importance of using more efficient materials, with reuse and recycling; that is, they allow a reduction in waste. It is worth clarifying that, from the IPCC, they indicated that materials whose manufacture does not generate greenhouse gases are still in the analysis stages or awaiting their respective approval for marketing.

But that's not all, thanks to the pandemic in some nations it was shown that the displacement of workers to their jobs can be reduced. They even noticed the ecological benefits of minimal travel, as scientists said when talking about the benefits of so-called “compact, high-density cities”, in which people can reach their destinations on foot or by bicycle and in 15 minutes.

Experts also warn that it will be necessary to slow down the horizontal growth of cities in order to focus on vertical buildings, which can maximize green spaces. They even point out the importance of adapting and updating existing buildings. Meanwhile, with regard to transport, they warned the importance of a migration towards low-carbon electric vehicles.

Global warming can still be stopped, according to a group of scientists

A popular phrase says that “the last thing that is lost is hope” and, in this regard, a group of researchers from the University of Melbourne put the magnifying glass on a study that was recently published in the journal Nature. According to his analysis, if countries do what they had promised in the Paris Agreement, the 2°C target could be reached by the end of the century (compared to the pre-industrial stage).

However, experts assured that this goal would be achieved if countries meet by reducing carbon emissions by 2030 and, in addition, they manage to turn their nations into “zero emitters” by the middle of the century. It is worth noting that, even if the 2°C target is reached, the planet will undergo profound changes. As they explained, with this increase there will be extreme weather events, there will be extinctions of animals and plants, there will be a melting of ice at the poles; effects that will have a direct impact on humanity. So far, according to UN data, more than 30 million people have already been displaced by the consequences of climate change.

Malte Meinshausen, lead author of the study and professor of climate at the University of Melbourne, said: “We can possibly keep warming below the symbolic 2-degree mark with promises on the table. That means, of course, that countries keep their promises.” “Of course, the 2-degree world requires countries to do what they promise. But cheaper wind and solar energy showed that carbon emissions cuts can come faster than expected and some countries will exceed the promised cuts,” the author explained.

In that tone, the scientist said: “The objectives and policies implemented can actually change future temperatures. I think it is important for countries to see optimism. Yes, there is hope.” Although he clarified: “Neither do we have a margin of error (limiting ourselves to just 2°C) nor do promises put us on a path close to 1.5 degrees”.

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