Climate changes - Maxicours

Climate changes

Objectifs
  • Découvrir un aspect de la notion d'étude innovations scientifiques et responsabilité
  • Approfondir sa réflexion sur le problème du réchauffement climatique
Points clés
  • Depuis 1950, la température moyenne de la Terre a augmenté de 1,5°C. Même si cela peut sembler anecdotique, les conséquences sont nombreuses et préoccupantes.
  • L'effet de serre participe à ce réchauffement climatique : les gaz carboniques que l'activité humaine produit a pour effet d'emprisonner une partie des rayons du soleil dans notre atmosphère, et donc leur chaleur ne s'évacue plus dans l'espace.
  • La COP 21 de 2015 a été un moment fort de prise de conscience des gouvernements : le premier accord internationale sur le sujet y a été signé !
  • La montée des eaux, la disparition annoncées de certaines espèces, les catastrophes naturelles, un rendement agricole diminué, l'accès restreint à l'eau potable... voici un aperçu de ce qui nous attend, à moins que, tous ensemble, nous arrivions à limiter la hausse des températures à 1,5°C.

Since the 1950s the Earth’s temperature has been rising by 1.5 degrees. Scientists say that the average temperature of our planet is about 15 degrees. Today it is nearly 17 degrees whereas in 1800 it was 13.5 degrees. If fluctuations are natural what is alarming today is that temperatures are now rising faster and faster. Indeed, the 20 warmest years have been recorded in the last 25 years! What makes temperatures rise so much and what are the consequences of these changes on our environment? This is what we are going to see here.

1. The Causes of Climate Change

The most important factor of climate change or global warming is the greenhouse effect. We know that the sun heats our planet but because of the numerous gas emissions we reject into the atmosphere a part of the sun’s rays are trapped by carbon dioxide in the atmosphere and consequently heat is retained and temperatures increase. If these rays were reflected into space the Earth’s temperature would decrease.

The greenhouse effect is due to gases released into the atmosphere by the industry, the agriculture but also by our cars, computers, chimneys, sprays...We all have a part to play to reduce theses emissions if we want to return to more normal temperatures.
This is of course partly due to the Industrial Revolution that started in the middle of the 18th century and which turned fog into smog in cities like London. But this period has also generated major improvements which must not be underestimated.

China (11,000 megatons), the USA (5,000) and Europe (3,500) are the world’s worst countries as far as carbon dioxide is concerned since they reject about 20,000 megatons into the atmosphere every year and it is high time they changed their policy on the environment, all the more as it takes decades to remove CO2 from the atmosphere.
Several hundred international environmental agreements exist and are essential in the international environmental regime.
There is also an annual event that has taken place since 1995, the Conference of Parties (COP), which is much concerned about climate change. It brings together 197 nations. But it was only in 2015 that the COP (COP 21 in Paris) had a historic outcome in the sense that the different parties concluded to the first international climate agreement.

2. The Consequences of Climate Change

The consequences are of course terrible and the most affected regions in the world are those situated near the Polar cap as the ice is melting. And this phenomenon has a terrible impact on the sea level which is rising and threatening low-lying islands which could be submerged by the end of the century. It is the domino effect.
Climate change also affects the flora and fauna. Flowers, plants and fruit come earlier and some animals like polar bears, seals or penguins have to find a new habitat as theirs is threatened by the melting of the ice.

Scientists are quite pessimistic when dealing with climate change and they think that temperatures could rise by 3 to 5 degrees by 2100, whereas 2 degrees is the limit! Heatwaves would last longer, the level of the sea would rise, crop productions would decrease, heavy rainfalls would increase, freshwater would be less available…
At the Conference of the Parties, scientists and governments have agreed that the limit should be 1.5 degrees.
As we have seen recently, hurricanes, floods, heat waves or droughts could become more and more frequent in the years to come if we do not react rapidly.

3. Conclusion

By damaging our planet and ignoring the problem of climate change linked to global warming we are damaging our lives, too. We cannot wait any longer to change things that could make a difference in the future. We have to think and act differently because there is much at stake. Our planet matters, we must not forget this obvious slogan and ensure that simple words become real acts.

Vous avez déjà mis une note à ce cours.

Découvrez les autres cours offerts par Maxicours !

Découvrez Maxicours

Comment as-tu trouvé ce cours ?

Évalue ce cours !

 

Des profs en ligne

quote blanc icon

Découvrez Maxicours

Exerce toi en t’abonnant

Découvrir le reste du programme

Des profs en ligne

  • 6j/7 de 17 h à 20 h
  • Par chat, audio, vidéo
  • Sur les matières principales

Des ressources riches

  • Fiches, vidéos de cours
  • Exercices & corrigés
  • Modules de révisions Bac et Brevet

Des outils ludiques

  • Coach virtuel
  • Quiz interactifs
  • Planning de révision

Des tableaux de bord

  • Suivi de la progression
  • Score d’assiduité
  • Un compte Parent