The COVID-19 pandemic has already triggered global health, economic, and social crises, clouding the sky of achieving the 2030 Agenda for Sustainable Development adopted by the United Nations (UN) in 2015 to improve human lives while protecting nature. Water, vital for all forms of life, is essential to public health and human well-being and smooth the path of ending poverty through food and energy security. Hence, we argued that global water security can serve as a shining star to guide policymakers through the overwhelming task of achieving the UN 2030 Agenda for Sustainable Development, currently hindered by the coronavirus outbreak. To quickly attain global water security while taking the accelerators of Sustainable Development Goal 6 (SDG6 “Clean Water and Sanitation”) into account, this study proposed different water-related interventions. To successfully implement the UN 2030 Agenda for Sustainable Development after the coronavirus pandemic, we call for immediate and sustainable interventions to act rapidly towards achieving water security and SDG6 worldwide and support the constant battle against the ongoing fight with COVID-19 and prepare for possible future pandemics.

Annual, seasonal and monthly variations in precipitation during the period 1911–2011 were evaluated using spatially interpolated monthly precipitation records at 165 stations with more than 30 years of data (of which 32 stations had 101 years of data referring to full length of study period). Historical trends and cyclic patterns of precipitation and links to teleconnection indices were analysed. The results show that annual precipitation in Finland increased by 0.92 ± 0.50 mm year⁻¹ (p < 0.05) during the study period (1911–2011), and showed negative relationships with the East Atlantic/West Russia (EA/WR) teleconnection pattern (ρ = −0.41, p < 0.05) through the years 1950–2011. However, there were spatial (north–south/east–west) differences between regions. The time cycle (λ) for annual precipitation cycles was estimated to 149 years (R²=0.15), and 1964 was indicated as the turning point from a negative (dry) to a positive (wet) phase. Analysis of seasonal and monthly cycles showed larger variations, depending mainly on teleconnection effects. Analysis of seasonal precipitation determined increasing trends for winter (by 0.46 ± 0.19 mm year⁻¹) and summer (by 0.32 ± 0.29 mm year⁻¹), while no clear trend was found for spring and autumn precipitation (p > 0.05). Winter precipitation was most strongly correlated with the North Atlantic Oscillation (NAO) index (ρ = 0.55, p < 0.05), while the EA/WR pattern was the most significant teleconnection index for precipitation variations in spring (ρ = −0.33, p < 0.05) and summer (ρ = −0.49, p < 0.05); the precipitation variability during autumn was negatively associated with the Scandinavia (SCA) pattern (ρ = −0.40, p < 0.05). The results clearly indicate that Finland has experienced wetter climate than normal conditions during recent decades, and precipitation in the Fenno-Scandinavian climate is controlled by a number of climate teleconnection indices, not just the NAO as previously assumed.

Annual and seasonal variations in surface air temperature (SAT) during the period 1961–2011 were analysed using daily mean temperature data sets from regular grid points (10 × 10 km²) throughout Finland. The Mann–Kendall nonparametric test was used to detect significant historical trends in SAT and Spearman's correlation coefficient (ρ) to test the relationships between SAT patterns and various atmospheric circulation patterns over the northern hemisphere. The results showed that mean annual SAT in Finland increased (p < 0.05) by 0.4 ± 0.2 °C per decade during the study period and that the SAT was significantly (ρ = 0.58, p < 0.05) positively correlated with the Arctic Oscillation (AO) index. However, there were spatial differences within Finland for both the trends and relationships with the atmospheric circulation. Analysis of seasonal mean SAT identified significant (p < 0.05) warming trends for both spring (by 0.4 ± 0.2 °C per decade) and summer (by 0.3 ± 0.2 °C per decade). Winter and spring mean SATs were most strongly (p < 0.05) correlated with the AO index (ρ = 0.72 and 0.42, respectively), while the most significant teleconnection pattern for mean SAT in summer was the East Atlantic (EA) pattern (ρ = 0.43, p < 0.05); and in autumn the EA/West Russia (WR) pattern (ρ = −0.59, p < 0.05). These results provide a detailed spatial picture of climate warming in Finland in recent decades and reveal that interannual variation of the SAT in Finland is closely linked with a number of atmospheric circulation patterns, not just the AO and North Atlantic Oscillation (NAO). Annual and cold‐season SAT are mainly influenced by the AO and NAO, whereas the EA, EA/WR, Scandinavia (SCA) and West Pacific (WP) patterns play an important role for warm‐season SAT.

Using daily mean temperature datasets applied at regular grid points (10 × 10 km²) throughout Finland for the period 1961–2011, interannual variations and trends in thermal growing season (GS) parameters, in terms of start (GSS), end (GSE) and length (GSL) and their relationships with various atmospheric teleconnection patterns (ATPs) were analysed. The GSL in Finland naturally increases from north to south, in association with earlier GSS and later GSE. However, the results showed that during the last 50 years, GSL on national scale in Finland significantly (p < 0.05) increased, at a rate of 0.30 ± 0.18 days year^–1. This change was mainly attributable to earlier GSS (0.16 ± 0.13 days year^–1, p < 0.05). The East Atlantic/West Russia (EA/WR) pattern was the most significant ATP influencing variations in GSS (ρ = 0.33), GSE (ρ = −0.42) and GSL (ρ = −0.33) on national scale in Finland. Statistically significant (p < 0.05) trends in GSL were all positive (increasing) and mainly observed in the centre (Oulu), upper east (Kuopio) and west (Jyväskylä), north (Rovaniemi‐Sodankylä) and south‐west coastal areas (Helsinki‐Turku‐Vaasa) of Finland. Increasing GSL in central, upper eastern and western Finland was mainly associated with significantly earlier GSS; that in the north with significantly later GSE; and that in the most south‐westerly areas with both earlier GSS and later GSE. These increases in GSL and corresponding shifts in GSS and/or GSE were significantly correlated with the East Atlantic (EA) pattern in northern and central Finland; with the EA/WR pattern in the south, south‐east and south‐west; and with the North Atlantic Oscillation (NAO) and the Arctic Oscillation (AO) in south‐west coastal areas. The results provide a detailed national and spatial picture of changes in GS parameters in Finland during the last 50 years and reveal that the interannual variability in GS parameters in Finland is strongly linked with a number of ATPs, such as the EA, EA/WR, NAO and AO.

Numerous studies have reported significant declines in snow resources in Finland and elsewhere during the 20th century. To identify the main climate factors controlling these declines in Finland, this study evaluated long-term variations and trends in wintertime climate, snowpack hydrological processes (SHPs) and continuous snow cover duration (CSCD), and their links to atmospheric circulation patterns (ACPs). Analyses were conducted using observed daily climatological time series and simulated SHPs at three stations in southern (Kaisaniemi), central (Kajaani) and northern (Sodankylä) Finland with about 100 years of data. The Mann-Kendall nonparametric test was used to detect significant trends, the Pearson's coefficient (r) to identify relationships within snow-related variables, and Spearman's coefficient (ρ) to measure correlations of these variables with ACPs. Sensitivity of the snow-related variables with projected changes in temperature and precipitation was assessed. The results showed increases in wintertime temperature only at Kaisaniemi, but decreases in wintertime precipitation, snowfall and snow water equivalent (SWE) and shorter CSCD at all stations. In general, variations in wintertime temperature were positively associated with the Arctic Oscillation (AO) and the North Atlantic Oscillation (NAO). However, wintertime precipitation showed significant relationships with the East Atlantic/West Russia (EA/WR), AO and West Pacific (WP) patterns in southern, central and northern Finland, respectively. SHPs and CSCD in southern Finland were associated with the same ACP influencing wintertime temperature (AO), and those in central and northern areas with the patterns influencing wintertime precipitation (EA, EA/WR and AO). Thus, declines in snow resources in Finland are mainly the result of reductions in snowfall owing to both wintertime warming and decreased precipitation at Kaisaniemi, while only to decreases in wintertime precipitation at Kajaani and Sodankylä stations. However, increase in precipitation (up to 30%) plays an important role in offsetting effects of temperature warming (up to 4 °C) on snow resource decline in Finland.