We’re In A Better Place To Fight Climate Change, But COP21 Is Just The Beginning

On the first day of this Paris climate change conference (COP21), keep in mind that these are the heads of state who, in Copenhagen in 2009, declared that they should bring about a global agreement on climate change that would limit global warming to below 2C, and even 1.5C. Here they are, meeting their responsibilities!

These two degrees are the main concern of the COP21. It is a serious challenge because scientists, and namely the IPCC, have shown that beyond this threshold, our planet will enter a downward spiral of imbalance, on several levels. Many things are therefore to be negotiated –especially this 2C objective– to ensure avoiding this point of no-return for the planet and humanity. Countries should commit to this to avoid the worst impacts of climate change.

More than 170 national contributions and commitments for 2025 or 2030 have been submitted by countries. This is a first that must be underscored; it speaks to an unprecedented mobilization on the part of most countries. These efforts, which would still lead the world towards global warming of around 3C by the end of the century, nonetheless convey the progress in ambition since the 2009 Copenhagen Summit.

“The next five years will be very important, and the longer we wait to put measures into effect, the harder it will become to minimize climate change.”

The second key issue which will require vigilance is that of development aid. In Copenhagen, the heads of state of rich countries said that they would commit to getting an $100 billion in aid per year by 2020. (This should be possible, since we know that every year, the fossil fuel sector receives approximately $500 billion in subsidies.) Now, it remains to be seen how this —> Read More

How Scientists Know Climate Change Is Happening

The Paris climate conference will set nations against each other, and kick off huge arguments over economic policies, green regulations and even personal lifestyle choices. But one thing isn’t up for debate: the evidence for climate change is unequivocal.

We still control the future, however, as the magnitude of shifting weather patterns and the frequency of extreme climate events depends on how much more greenhouse gas we emit. We aren’t facing the end of the world as envisaged by many environmentalists in the late 1980s and early 1990s, but if we do nothing to mitigate climate change then billions of people will suffer.

Causes of climate change

Greenhouse gases absorb and re-emit some of the heat radiation given off by the Earth’s surface and warm the lower atmosphere. The most important greenhouse gas is water vapor, followed by carbon dioxide and methane, and without their warming presence in the atmosphere the Earth’s average surface temperature would be approximately -20°C. While many of these gases occur naturally in the atmosphere, humans are responsible for increasing their concentration through burning fossil fuels, deforestation and other land use changes. Records of air bubbles in ancient Antarctic ice show us that carbon dioxide and other greenhouse gases are now at their highest concentrations for more than 800,000 years.

Evidence for climate change

The Intergovernmental Panel on Climate Change (IPCC) presents six main lines of evidence for climate change.

  1. We have tracked the unprecedented recent increase in the amount of atmospheric carbon dioxide and other greenhouse gases since the beginning of the industrial revolution.

  2. We know from laboratory and atmospheric measurements that such greenhouse gases do indeed absorb heat when they are present in the atmosphere.

  3. We have tracked significant increase in global temperatures of at least 0.85°C and a sea level rise of 20cm —> Read More

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