Climate change alters teleconnections

TL;DR

This study uses statistical methods to show that human-induced climate change has significantly altered teleconnection patterns affecting global weather, with implications for future climate projections.

Contribution

It demonstrates that shifts in teleconnection patterns are attributable to anthropogenic forcing and assesses regional impacts of climate modes on these changes.

Findings

Changes in teleconnection patterns exceed natural variability in many regions

Anthropogenic forcing significantly influences climate variability patterns

Projections indicate further alterations in teleconnections due to climate change

Abstract

Internal modes of climate variability, such as El Ni\~no and the North Atlantic Oscillation, can have strong influences upon distant weather patterns, effects that are referred to as "teleconnections". The extent to which anthropogenic climate change has and will continue to affect these teleconnections, however, remains uncertain. Here, we employ a covariance fingerprinting approach to demonstrate that shifts in teleconnection patterns affecting monthly temperatures between the periods 1960-1990 and 1990-2020 are attributable to anthropogenic forcing. We further apply multilinear regression to assess the regional contributions and statistical significance of changes in five key climate modes: the El Ni\~no-Southern Oscillation, North Atlantic Oscillation, Southern Annular Mode, Indian Ocean Dipole, and the Pacific Decadal Oscillation. In many regions, observed changes exceed what would be expected from natural variability alone, further implicating an anthropogenic influence. Finally, we provide projections of how these teleconnections will alter in response to further changes in climate.