The importance of continuous comprehensive Integrated observations: from feedback loop analysis to CarbonSink+

The Earth is facing several environmental challenges on a global scale, often called “Grand Challenges” (https://www.wcrp-climate.org/grand-challenges/). The growing population (https://pdp.unfpa.org) needs fresh air, fresh water, food and energy, while at the same time climate is changing, many cities have challenges with air quality, biodiversity is decreasing and supplies of fresh water, food and energy are diminishing. Since these Grand Challenges are highly connected and interlinked, not only with each other but also with e.g. pandemics, they cannot be solved separately since potential solutions are tightly coupled with each other. However, the solutions may also include unexpected trade-offs. Therefore, integrated, comprehensive, big open data are required, together with a research and innovation framework in which a multidisciplinary research with critical mass of scientists utilising proper resources is connected to fast-tracked policy making and wide stakeholder community. This allows aiming for practical solutions based on deep scientific understanding. The global challenges are intimately linked to interactions and feedbacks between the different compartments of the planet Earth at different spatial and temporal scales. Fundamentally, the atmosphere is closely interconnected with various other parts of the Earth, including biosphere, hydrosphere, cryosphere and lithosphere as well as urban surfaces over a range of time and spatial scales varying from seconds to millennia. The sources, sinks and atmospheric concentrations of reactive trace gases, greenhouse gases and aerosol particles depend strongly on each other via physical, chemical and biological processes. Furthermore, both human actions and natural feedback mechanisms between the biosphere and atmosphere have substantial impacts on interactions between these atmospheric constituents and their influences on air quality and climate. To be able to meet global grand challenges we need comprehensive open data with proper metadata, along with open science. The large data sets from ground-base in situ observations, ground and satellite remote sensing and multiscale modelling need to be utilized seamlessly. Here we demonstrate the power of the SMEAR (Station for Measuring Earth surface – Atmosphere Relations) concept via several examples, such as detection of new particle formation and their subsequent growth, quantifying atmosphere-ecosystem feedback loops, combining comprehensive observations with emergency science and services, as well as studying the effect of COVID restrictions on different air quality and climate variables. Furthermore we show how from feedback loop analyses we develop CarbonSink+ concept. The future needs and the potential of comprehensive observations of the environment are also summarized.