  This review article summarizes the advancement in the studies of
Earth-affecting solar transients in the last decade that encompasses most of
solar cycle 24. The Sun Earth is an integrated physical system in which the
space environment of the Earth sustains continuous influence from mass,
magnetic field and radiation energy output of the Sun in varying time scales
from minutes to millennium. This article addresses short time scale events,
from minutes to days that directly cause transient disturbances in the Earth
space environment and generate intense adverse effects on advanced
technological systems of human society. Such transient events largely fall into
the following four types: (1) solar flares, (2) coronal mass ejections (CMEs)
including their interplanetary counterparts ICMEs, (3) solar energetic particle
(SEP) events, and (4) stream interaction regions (SIRs) including corotating
interaction regions (CIRs). In the last decade, the unprecedented multi
viewpoint observations of the Sun from space, enabled by STEREO Ahead/Behind
spacecraft in combination with a suite of observatories along the Sun-Earth
lines, have provided much more accurate and global measurements of the size,
speed, propagation direction and morphology of CMEs in both 3-D and over a
large volume in the heliosphere. Several advanced MHD models have been
developed to simulate realistic CME events from the initiation on the Sun until
their arrival at 1 AU. Much progress has been made on detailed kinematic and
dynamic behaviors of CMEs, including non-radial motion, rotation and
deformation of CMEs, CME-CME interaction, and stealth CMEs and problematic
ICMEs. The knowledge about SEPs has also been significantly improved.
