A sequence of monsoon surges struck Pakistan and Northwestern India during late July‐early August 2010. The unusually heavy monsoon rainfall resulted in record‐breaking floods, which affected 20 million people with a death toll of near 3000. Simultaneously, a long‐lived blocking high appeared over Europe and Russia in middle June and persisted for nearly two months. Extreme flooding occurred when the southward penetration of extratropical potential vorticity in the deep trough east of the European blocking and the tropical monsoon surges arrived concurrently in Pakistan. This study demonstrates that the interaction between the tropical monsoon surges and the extratropical disturbances downstream of the European blocking was the key factor leading to the severe flooding in Pakistan. The 2010 La Niña condition contributed indirectly to the flooding by inducing a low‐level easterly anomaly in South and Southeast Asia, which weakened eastward moisture transport and helped enhance moisture transport (convergence) to (in) the Northern Arabian Sea and Pakistan.

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This study analyzes the influence of El Niño-Southern Oscillation (ENSO) on the activity of tropical cloud clusters (TCCs) in the western North Pacific (WNP). A TCC must have at least one embedded mesoscale convective system and it must persist for more than 24 hours. In all, 2,248 TCCs were identified during July-October 1981-2009. While more (less) TCCs form in the eastern (western) part of the WNP during El Niño years than during normal years, the converse is true during La Niña years. The ratio of tropical cyclone (TC) numbers to TCC numbers (genesis productivity) was 27.3%, higher than found in previous study. TC genesis productivity does not correlate with the Oceanic Niño Index even in subregions of the WNP. The influence of ENSO on TC numbers in each subregion of the WNP was mainly due to changes in TCC number, not changes in TC genesis productivity.

Non-technical summaryWe summarize some of the past year's most important findings within climate change-related research. New research has improved our understanding about the remaining options to achieve the Paris Agreement goals, through overcoming political barriers to carbon pricing, taking into account non-CO 2 factors, a well-designed implementation of demand-side and nature-based solutions, resilience building of ecosystems and the recognition that climate change mitigation costs can be justified by benefits to the health of humans and nature alone. We consider new insights about what to expect if we fail to include a new dimension of fire extremes and the prospect of cascading climate tipping elements.