How serious is the sea level rise threat?

There have been numerous studies pointing to the connection between climate change and sea level rise, warning the world that in not so far future from now many parts of the world will likely experience severe flooding if global temperatures continue to grow.

The latest such study comes from Michael Schaeffer of Climate Analytics and Wageningen University who claims that even if we limit global temperature increase to 2 degrees Celsius, global sea levels will still continue to rise, reaching between 1.5 and 4 metres above present-day levels by the year 2300.

He also concluded that if world were to limit rise in global temperatures to below 1.5 degrees Celsius this would likely halve sea-level rise by 2300, compared to a 2-degree scenario.

These studies attract plenty of public attention, despite being just assumptions of future „could be“ scenarios. The scientists admit the fact that it is very difficult to quantify the level of sea level rise in years to come, especially because it is still uncertain whether global sea level found for the past could be carried into the future.

These future estimates, despite still being connected with significant level of uncertainty, all point to the fact that we must take sea level rise issue far more seriously than we are doing it today.

If we continue business as usual scenario sea level rise will spell major problems for many coastal areas all over the globe. Coastal communities are already running out of time to adapt to global rise in sea levels.

The affected areas will not only be low lying deltaic countries like Bangladesh and Netherlands, and small islands, but also major cities such as New York. Stefan Rahmstorf of the Potsdam Institute for Climate Impact Research, said that one metre sea level rise would increase the frequency of severe flooding from once per century to once every three years for New York City.

How much does deforestation contribute to climate change?

The emissions coming from deforestation play significant role in climate change phenomenon though not as much as previously predicted. According to a latest NASA study the previous estimates about the contribution of emissions from deforestation in total worldwide man-made carbon emissions need to be significantly reduced to get the real picture.

The NASA used satellite data in order to determine the actual contribution of deforestation in global emissions in period from 2000-2005. Their conclusion was that deforestation accounted for approximately 10 percent of the total worldwide man-made carbon emissions in the period from 2000-2005.

This percentage is roughly one third of previously published estimates. It also has to be said that is the first study that used satellite data while previous studies mostly used tabular bookkeeping models to obtain the numbers.

Though this is a significantly smaller percentage than previously thought this doesn't change the fact that deforestation is still one of the top climate change contributors.

Deforestation is primarily connected with tropical rainforests. These ancient forests are huge carbon sinkers and absorb large quantities of CO2 from the atmosphere. This means that the destruction of these forests not only creates new emissions but also reduces the total forests cover, doubling the negative impact on climate change.

We are still talking about the losses of millions of hectares of forest per year which represents a major environmental issue, not only because of the climate change issue, but also because tropical forests are areas with the richest biodiversity on our planet, meaning that many plant and animal species will lose their homes if we continue this path of destruction.

The scientists soon plan to update this study with information whether the carbon emissions from deforestation increased or decreased in the second half of the 2000s.

Increased forest cover doesn't always mean better carbon storage

The currently dominant opinion is that the more forests we plant the more carbon it will be stored. This is true in most cases but not always as the latest study by the University of Exeter shows.

Dr Iain Hartley from the University of Exeter argues that the fact that Arctic is becoming more and greener isn't beneficial for climate change because the carbon stored in Arctic tundra could be released into the atmosphere by new trees growing in the warmer region, which could exacerbate climate change impact even further.

The greening usually results in more carbon dioxide (CO2) being sink from the atmosphere, therefore helping to reduce the impact of climate change but this is not the case with Arctic tundra.

The expansion of forest into Arctic tundra could stimulate decomposition rates in soils leading to significant release of carbon dioxide into the atmosphere.

Tundras are specific because their soil contains plenty of stored organic matter, due to slow decomposition, and the new trees stimulate the decomposition of this matter leading to more release of CO2 into the atmosphere.

The scientists believe that Arctic soils currently store more carbon than is present in the atmosphere and so the release of this stored carbon could have devastating impact on climate change.

The role of soil conditions is yet to be fully understood in climate change equation. By the current looks of it planting new trees in Arctic tundra doesn’t look to be beneficial for climate change, in fact, it could lead to more bad climate change news. It is up to science to determine whether this pattern is confined strictly to Arctic or not.