Sentences with phrase «dioxide than human activities»

Scientists complained that the programme makers distorted evidence, and made elementary mistakes such as claiming that volcanoes produce more carbon dioxide than human activities, when in fact they produce less than 2 % of that caused by the burning of fossil fuels.

Not exact matches

In animal models, exposure to cigarette smoke or nicotine during fetal development alters the expression of the nicotinic acetylcholine receptor in areas of the brainstem important for autonomic function, 28 alters the neuronal excitability of neurons in the nucleus tractus solitarius (a brainstem region important for sensory integration), 29 and alters fetal autonomic activity and medullary neurotransmitter receptors.30 In human infants, there are strong associations between nicotinic acetylcholine receptor and serotonin receptors in the brainstem during development.31 Prenatal exposure to tobacco smoke attenuates recovery from hypoxia in preterm infants, 32 decreases heart rate variability in preterm33 and term34 infants, and abolishes the normal relationship between heart rate and gestational age at birth.33 Moreover, infants of smoking mothers exhibit impaired arousal patterns to trigeminal stimulation in proportion to urinary cotinine levels.35 It is important to note also that prenatal exposure to tobacco smoke alters the normal programming of cardiovascular reflexes such that there is a greater - than - expected increase in blood pressure and heart rate in response to breathing 4 % carbon dioxide or a 60 ° head - up tilt.36 These changes in autonomic function, arousal, and cardiovascular reflexes might all increase an infant's vulnerability to SIDS.

While scientists and policy experts debate the impacts of global warming, Earth's soil is releasing roughly nine times more carbon dioxide to the atmosphere than all human activities combined.

The seven - day rainfall total from Harvey was as much as 40 percent higher than rainfall from a similar storm would have been decades ago, before human activity caused atmospheric carbon dioxide levels to spike, according to a study published yesterday in Geophysical Research Letters.

The reason for the accumulation is simple: Human activities are emitting more carbon dioxide than the planet's natural processes (uptake by plants and the ocean) can remove.

The problem is that human activities have disrupted the natural balance, pumping more carbon dioxide into the atmosphere than there would be naturally: levels have been raised measurably over the last century.

[79] Natural sources of carbon dioxide are more than 20 times greater than sources due to human activity, [80] but over periods longer than a few years natural sources are closely balanced by natural sinks, mainly photosynthesis of carbon compounds by plants and marine plankton.

The logic is clear: If the Earth has already warmed more than we thought due to human activities, then there's even less remaining carbon dioxide that we can emit and still avoid 2 degrees of warming.