The 2024 state of the climate report: Perilous times on planet Earth

Keskiviikko 9.10.2024 klo 14.08 - Mikko Nikinmaa

William J. Ripple et al. have published the above report in Bioscience , (https://doi.org/10.1093/biosci/biae087). I place its conclusions below.

Despite six IPCC reports, 28 COP meetings, hundreds of other reports, and tens of thousands of scientific papers, the world has made only very minor headway on climate change, in part because of stiff resistance from those benefiting financially from the current fossil-fuel based system. We are currently going in the wrong direction, and our increasing fossil fuel consumption and rising greenhouse gas emissions are driving us toward a climate catastrophe. We fear the danger of climate breakdown. The evidence we observe is both alarming and undeniable, but it is this very shock that drives us to action. We recognize the profound urgency of addressing this global challenge, especially the horrific outlook for the world's poor. We feel the courage and determination to seek transformative science-based solutions across all aspects of society. Our goal is to provide clear, evidence-based insights that inspire informed and bold responses from citizens to researchers and world leaders.

Rapidly phasing down fossil fuel use should be a top priority. This might be accomplished partly through a sufficiently high global carbon price that could restrain emissions by the wealthy while potentially providing funding for much-needed climate mitigation and adaptation programs. In addition, pricing and reducing methane emissions is critical for effectively mitigating climate change. Methane is a potent greenhouse gas, and unlike carbon dioxide, which persists in the atmosphere for centuries, methane has a relatively short atmospheric lifetime, making reductions impactful in the short term (Shindell et al. 2024). Drastically cutting methane emissions can slow the near-term rate of global warming, helping to avoid tipping points and extreme climate impacts.

In a world with finite resources, unlimited growth is a perilous illusion. We need bold, transformative change: drastically reducing overconsumption and waste, especially by the affluent, stabilizing and gradually reducing the human population through empowering education and rights for girls and women, reforming food production systems to support more plant-based eating, and adopting an ecological and post-growth economics framework that ensures social justice (Table S4). Climate change instruction should be integrated into secondary and higher education core curriculums worldwide to raise awareness, improve climate literacy, and empower learners to take action. We also need more immediate efforts to protect, restore, or rewild ecosystems.

The surge in yearly climate disasters shows we are in a major crisis with worse to come if we continue with business as usual. Today, more than ever, our actions matter for the stable climate system that has supported us for thousands of years. Humanity's future depends on our creativity, moral fiber, and perseverance. We must urgently reduce ecological overshoot and pursue immediate large-scale climate change mitigation and adaptation to limit near-term damage. Only through decisive action can we safeguard the natural world, avert profound human suffering, and ensure that future generations inherit the livable world they deserve. The future of humanity hangs in the balance.

Broken water cycle

Tiistai 29.8.2023 klo 15.42 - Mikko Nikinmaa

The civilization as we know it is dependent on appropriate availability of water. Water availability has been adequate and constant for the past 10000 years. It has enabled the development of agriculture followed by industrialization. Feeding the billions of people has been possible, as there has been enough water at right time.

However, it appears now that humans are breaking the water cycle. Intensive agriculture is using more fresh water than would be available. Climate change affects the timing, duration and place of precipitation. Also, glaciers, which are the source of many rivers, have melted to such an extent that the river flow is reduced. Deforestation affects the rains in the areas in the vicinity. All in all, although roughly ¾ of Earth’s surface is covered with water, the cycle of fresh water, needed for civilization as we know it, seems to be in peril.

It is easy to blame climate change for the fresh water problems, but it is only part of the problem. Because of climate change, droughts and heat spells become more common, heavy rains come irregularly and at unexpected places. Often they occur after severe drought, whereby the soil cannot bind the water, which flows to the sea. An important component of the water cycle in equilibrium is that the upper soil is moist. It is then able to bind additional water.

As for many other resources, mankind is overusing water. Intensive irrigation and domestic water use have emptied Jordan, Sacramento River, Colorado River etc., caused almost total disappearance of Dead Sea and Aral Sea, and lowered ground water level to such an extent that Earth’s poles have shifted slightly.

With regard to deforestation, rainforests are much more than important carbon dioxide sinks. They suck moisture from soil, liberate water in the air, and thus cause development of rains in the surrounding areas. With deforestation, this cycle is weakened with the result that rainforest may turn to savannah. It is estimated that when ¼ of the forest is cut, this happens. We are nearing this  percentage both for Amazonas and Congo rainforest.

In view of the disturbed water cycle, one should make every effort to diminish water use in any area to the amount which is certainly replaced by inflow. In terms of plants that are grown, this means that we should at least stop using cotton products, as there is already a sustainable alternative for cloth fibre, i.e., wood fibre. Deforestation of rainforests should be stopped. In this context it would be valuable to be able to stop population growth, as it inevitably causes the need for increased agricultural production, which is a primary reason for breaking water cycle.

It is only 5 % - why the human addition to carbon dioxide load matters?

Tiistai 5.4.2022 klo 14.40 - Mikko Nikinmaa

The people denying that human influence has little or nothing to do with climate change invariably point out that the addition by humans represents only 5 % of the total production of carbon dioxide at any given moment. Surely, such a small increment cannot have an effect attributed to it.

Another group of people say that the climate change problem is only caused by rich industrialized nations, and has nothing to do with population growth in poor areas of the world. The richest 10 % of the world’s population cause 1/3 of all greenhouse gas emissions while poorest 50 % emit only 15 % of world’s total human-emitted carbon dioxide.

Both of these statements are drastically wrong, and below I try to indicate why. In both cases the ultimate reason is the disturbance of the carbon cycle. In undisturbed nature the carbon cycle is in equilibrium. The carbon dioxide produced in the respiration of all organisms is used up in the photosynthesis and oxygen is produced.

A 5 % increase in carbon dioxide production, because of fossil fuel use, generates a huge disequilibrium, which we now see as climate change. In undisturbed nature, the disequilibrium would slowly (in hundreds to thousands of years) be corrected by an increase of green vegetation to generate a new equilibrium. The 5 % disequilibrium is so huge than the return to equilibrium lasts a long time if it is possible at all. Tipping point can be caused by the disequilibrium such that the temperature increase is so large that a net increase in photosynthesis cannot be achieved. In such a case temperature increase just continues and as worst, Earth becomes similar to Venus.

A disturbance of the carbon cycle can also result from the increased use of land by humans. This is what is currently happening in poor areas, where population increases. The carbon dioxide uptake and oxygen production by green plants is currently decreasing, mainly because of deforestation (but also as agricultural land erodes or is turned to human settlements). This causes similar worsening of the climate change situation as the fossil fuel use of the industrialized nations.

We live in one world with limits, and we should all work for the wellbeing of the planet. We should stop blaming others, which is the easy thing to do, and instead aim at reducing inequality and excessive consumption.

Human actions cause climate change even when fossil fuel use is not involved

Tiistai 22.3.2022 klo 18.24 - Mikko Nikinmaa

Although there are still many people thinking that climate change is not occurring or at least man has nothing to do with it, there are many problems that man is causing which accelerate temperature increase, and which could be avoided by human action. The points below are such, and can be very important in driving many parts of the world uninhabitable because of either too high temperature or drought or both. So, even people who do not believe that fossil fuel burning causes temperature increase, should accept that the following affect climate and that humans could take actions to combat the changes.

1. Because of massive deforestation, Amazon rainforest appears to near tipping point, where the rainforest turns to savannah. Boulton et al write in recent Nature Climate Change (Nature Climate Change 12: 271-278; 2022) how the resilience of Amazon rainforest has decreased dramatically since the early 2000s. Other studies have also indicated that whereas we have always considered Amazonas to be a carbon sink, it has recently turned into a net emitter of carbon dioxide. The major reason for carbon dioxide emissions is the widespread forest burning.

If the rainforest starts turning to savannah, naturally the first thing that happens is that the plant and animal species living in rainforest die off, so the biodiversity decreases radically. But even if this doesn’t concern the people, who deforest Amazonas, the following should. The water cycle of South America depends on the rainforest. If Amazonas turns into savannah, because more agricultural land is wanted, the whole South America dries up, and many areas become unsuitable for agriculture (too dry). So, by trying to increase agricultural area, greedy people end up decreasing it.

And because of the loss of one big carbon dioxide sink, the temperature throughout the world increases even if fossil fuels had nothing to do with climate change.

2. Two events happening to the oceans are also causing increased carbon dioxide levels and consecutive temperature increase even without the input of fossil fuel burning, and both depend mainly on human action. First, almost a half of the photosynthetic carbon dioxide use is due to the photosynthesis of (mainly unicellular) algae. Because of the pollution, it is estimated that the oceanic photosynthesis has decreased by 10-15 %. This increased carbon dioxide load is one factor affecting global temperatures, and could be avoided by human action – proper water purification. Second, world’s oceans are overfished. The global carbon cycle depends a lot on fish accumulating carbon. When they die, the accumulated carbon sinks to the bottom of the oceans and stays there for thousands of years. As overfishing reduces fish populations, this removal of carbon from ocean surface is reduced, and the reduced removal is seen as an increase in global carbon dioxide level, leading to temperature increase.

Again this takes place without any change in fossil fuel use, but is entirely human-caused.

3. There are further a couple of vicious circles, which increasingly take place, if human actions fail to limit temperature increase. Temperature increase decreases the carbon dioxide solubility in water. Thus, if temperature increases, more carbon dioxide is given up from the ocean, leading to further temperature increase etc. There are huge natural gas (methane) stores below the permafrost. Methane is a very potent greenhouse gas. If temperature increases so that permafrost starts melting, the methane below is liberated, causes further temperature increase leading to further permafrost melting and methane liberation etc.

To prevent these vicious circles from happening, climate deeds are important even today with the brutal Russian attack to Ukraine. In the best case, it can actually speed up the change from fossil fuel-based to green energy production.