Research on Climate Change and Its Impacts Needs Freedom of Research

Abstract

Climate change captured my interest as a teenager when, at the dining table, my dad talked about potential anthropogenic climate changes. He brought up subjects such as “climate could change if the Siberian Rivers were to be deviated to the South for irrigation of the (semi) arid areas of the former Soviet Union”. Other subjects were afforestation in the Sahel to enhance precipitation recycling, deforestation in the Tropics that could have worldwide impacts on climate, the local climate impacts of the Merowe High Dam in its vicinity and downstream, Atlantropa, a new ice age, and the increase in days with sunshine after the introduction of the high-chimney policy in the Rhein-Ruhr area, just to mention a few. Various investigations from different, independent researchers showed evidence for climate change at various spatial and temporal scales. The causes of climate change are manifold. They range from astronomical changes, changes in the distribution of continents including mountain ranges and heights, volcanic eruptions, evolution of the biosphere, to anthropogenic impacts, among many others. Anthropogenic impacts encompass, but are not limited to, emission of greenhouse gases (e.g., water vapor, carbon dioxide, methane, nitrous oxide, ozone) as well as trace gases that are precursors for aerosols, land-cover changes for food production, grazing, hunting, wood harvesting, housing, recreation, water storage, and transportation, as well as openpit mining, oil and gas drilling. Even emission-control measures, to protect human health, may impact the local, and potentially regional, climate as aerosol-precursor concentrations, and particle concentrations and their composition may change. Teleconnections can propagate regional change signals to areas far downwind of the initial changes. This means climate change needs no passport or visa to enter another country. We are all in it together. A habitable, reachable planet is hard to find. Thus, just the idea that the activity of humankind may impact the climate of our “spaceship” Earth can be frightening, even terrifying, and may cause stress. As with handling any other stress, it is important to stay cool. Doing so enables researchers to gather the facts (knowledge, data), think, build hypotheses and test them, identify gaps in the knowledge, think about what data one would need to close these gaps, build new hypotheses, gather further data and/or develop and improve models to test the hypotheses, and so on. Scientific data-based knowledge is critical for understanding natural and anthropogenic impacts on climate, feedback mechanisms between various processes and components of the Earth system, sensitivities, uncertainties, and the magnitude of various natural and anthropogenic impacts. Such understanding and knowledge are urgent needs for cost-effective and ethical decisions for all living beings on Earth, and a growing world population with its growing water, food, and energy demands. Being aware that climate change has always happened, humankind cannot afford to split into groups that are not willing and/or even not able to talk to each other. Humankind cannot afford that their scientists waste their time on being captivated by interest groups, and petty discussions for/about funding, and lose the freedom of research. Scientific debate is fruitful, necessary and will always exist. Recall when physicists disputed about the wave and particle structure of electro-magnetic waves, or the validity of the general theory of relativity. In the end, it turned out both times that both arguments were right. The discrepancies were due to the experimental design and the point they were coming from. Most likely climate science is at the dawn of something similarly exciting. In the interest of freedom of research and progress in climate research, we should not ask to which group a scientist and/or his/her research “belongs”. Instead, we, as the climate science community, have to ask questions like: Why do we get results that have to be interpreted in one or the other way? Did we, by accident, capture a special case such as mechanics within the relativity theory? Are we overlooking something? What impacts have closing/installing of observational sites and improved measurements for knowledge about the climates of the globe? Can we demonstrate that Earth system models, climate models or even very simple models are able to capture past observations? Which opportunities have we overlooked and tools do we have available that could advance climate research? For instance, a great, often overlooked, capability of models is that they can be used to learn/examine what is important when, and where. If the same hypothesis is once rejected based on a dataset used, and once accepted based on another dataset, the logical next step is to compare the two datasets, and to investigate the reasons. Is one or are both datasets biased and/or contaminated by changes in the instrumentation, the measurement protocol, or in the environment other than climate change? What different information do the two datasets hold that led to the different answers? Can we find other data to figure out whether we are dealing with a special case? Are we overlooking a process that only becomes important under certain circumstances? Are we facing something similar to the UV-catastrophe in the Rayleigh-Jeans law? Climate wants to be a forum to stimulate such questions, ideas, and discussions.